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650+ Adjectives That Start With O

    Adjectives That Start With O

    Adjectives are words that describe or modify another person or thing in the sentence. The articles that follow will introduce you to some adjectives that start with O.

    You might be surprised to learn that there are so many adjectives that start with O. After reading this article, you will be able to add some new words to your vocabulary.

    Some of the adjectives that start with O include:

    obese, objective, oblong, observant, obsolete, obstinate, occasional, offensive, optimistic, and organic.

    These are only a few of the many adjectives that start with O. With a little practice, you will be able to use these words to improve your writing.

    Adjectives That Start With The Letter O

    If you’re looking for a list of adjectives that start with O, you’ve come to the right place! Here are some of our favorites:

    Adjectives That Start With O
    • Outstanding: This adjective is used to describe someone who is exceptional or excellent.
    • Objective: This adjective describes someone who is impartial or unbiased.
    • Optimistic: This adjective describes someone who is hopeful and positive.
    • Organized: This adjective is used to describe someone who is tidy and efficient.
    • Outgoing: This adjective is used to describe someone who is sociable and extroverted.
    • Overjoyed: This adjective is used to describe someone who is extremely happy.
    Read:  Describing Words for a Couple: Examples and Adjectives

    78 Adjectives That Start With OA, OB

    OafishStupid, uncultured, or clumsy.
    OakA tree that bears acorns as fruit, and typically has lobed deciduous
    leaves. Oaks are common in many north temperate forests and are an
    important source of hard and durable wood used chiefly in construction,
    furniture, and (formerly) shipbuilding.
    OakenMade of timber from the oak tree.
    Oareda long pole with a broad blade at one end used for propelling or steering a
    boat
    OatenMade with or containing oats.
    ObbligatoAn instrumental part, typically distinctive in effect, which is integral to
    a piece of music and should not be omitted in performance.
    ObconicIn the form of an inverted cone.
    ObconicalIn the form of an inverted cone.
    Obcordate(of a leaf) in the shape of a heart with the pointed end at the base.
    ObdurateStubbornly refusing to change one’s opinion or course of action.
    ObedientComplying or willing to comply with orders or requests; submissive to
    another’s will.
    ObeliscalOf the nature of or resembling an obelisk; of or relating to an obelisk.
    ObeseVery fat or overweight.
    Objective(of a person or their judgment) not influenced by personal feelings or
    opinions in considering and representing facts.Grammar A thing aimed at or sought; a goal.the objective
    ObjurgativeObjurgatory.
    Oblanceolate(especially of leaves) lanceolate with the more pointed end at the base.
    Oblate(of a spheroid) flattened at the poles.A person dedicated to a religious life, but typically having not taken full
    monastic vows.
    ObligateBind or compel (someone), especially legally or morally.US Restricted to a particular function or mode of life.
    ObligatedBind or compel (someone), especially legally or morally.US Restricted to a particular function or mode of life.
    ObligatoAn instrumental part, typically distinctive in effect, which is integral to
    a piece of music and should not be omitted in performance.
    ObligatoryRequired by a legal, moral, or other rule; compulsory.
    ObligedMake (someone) legally or morally bound to an action or course of action.
    ObligingWilling to do a service or kindness; helpful.
    ObliqueNeither parallel nor at a right angle to a specified or implied line;
    slanting.Grammar Not explicit or done in a direct way.A muscle neither parallel nor perpendicular to the long axis of a body or
    limb.British
    ObliterateDestroy utterly; wipe out.
    ObliviousNot aware of or not concerned about what is happening around one.
    OblongAn object or flat figure in an elongated rectangle or oval shape.Having an elongated shape, as a rectangle or an oval.
    ObnoxiousExtremely unpleasant.
    Obovate(of a leaf) ovate with the narrower end at the base.
    ObovoidObovate in cross-section; inversely ovoid.
    Obscene(of the portrayal or description of sexual matters) offensive or disgusting
    by accepted standards of morality and decency.
    ObscurantA person who deliberately prevents the facts or full details of something
    from becoming known; an obscurantist.Something used to hinder visibility.Deliberately preventing the facts or full details of something from
    becoming known; obscurantist.Having the effect of hindering visibility.
    ObscurantistA person who deliberately prevents the facts or full details of something
    from becoming known.Deliberately preventing the facts or full details of something from
    becoming known.
    ObscureNot discovered or known about; uncertain.Keep from being seen; conceal.
    ObsequentCompliant, yielding, obedient; deferential, servile.Of a stream, stream valley, or drainage pattern
    ObsequiousObedient or attentive to an excessive or servile degree.
    ObservableAble to be noticed or perceived; discernible.
    ObservantQuick to notice things.Adhering strictly to the rules of a particular religion, especially Judaism.A member of a branch of the Franciscan order that followed a strict rule.
    ObservedNotice or perceive (something) and register it as being significant.reporting verbFulfill or comply with (a social, legal, ethical, or religious obligation)
    ObservingNotice or perceive (something) and register it as being significant.reporting verbFulfill or comply with (a social, legal, ethical, or religious obligation)
    ObsessedPreoccupy or fill the mind of (someone) continually, intrusively, and to a
    troubling extent.
    ObsessiveOf the nature of an obsession.A person who is affected by an obsession.
    ObsoleteNo longer produced or used; out of date.Biology Cause (a product or idea) to be or become obsolete by replacing it with
    something new.
    ObstetricRelating to childbirth and the processes associated with it.
    ObstinateStubbornly refusing to change one’s opinion or chosen course of action,
    despite attempts to persuade one to do so.
    ObstreperousNoisy and difficult to control.
    ObstructedBlock (an opening, path, road, etc.); be or get in the way of.
    ObstructiveCausing a blockage or obstruction.Causing or tending to cause deliberate difficulties and delays.
    ObstruentA fricative or plosive speech sound.
    ObtainableAble to be obtained.
    Obtect(of an insect pupa or chrysalis) covered in a hard case with the legs and
    wings attached immovably against the body.
    ObtrusiveNoticeable or prominent in an unwelcome or intrusive way.
    ObtundentA medicinal substance that has a blunting or dulling effect (on
    inflammation, pain, etc.); (Dentistry) a local anaesthetic.Having the property of dulling or blunting; acting as an anaesthetic.
    ObtuseAnnoyingly insensitive or slow to understand.(of an angle) more than 90° and less than 180°Not sharp-pointed or sharp-edged; blunt.
    ObumbrateTo overshadow; to shade, darken; to obscure. (literal and figurative).
    ObverseThe side of a coin or medal bearing the head or principal design.The opposite or counterpart of a fact or truth.Of or denoting the obverse of a coin or medal.Corresponding to something else as its opposite or counterpart.Biology
    ObviatingRemove (a need or difficulty)
    ObviousEasily perceived or understood; clear, self-evident, or apparent.
    Obvolute(of a leaf) having a margin that alternately overlaps and is overlapped by
    that of an opposing leaf.
    OarlessOblatoryObservational
    ObeisantObligationalObsessional
    ObjectionableObliteratedObsessive-Compulsive
    ObjectivistObliteratingObsolescent
    ObjectivisticObliterativeObstetrical
    ObjurgatoryObreptitiousObtuse-Angled
    Obtuse-Angular

    56 Adjectives Starting With OC

    OccasionalOccurring, appearing, or done infrequently and irregularly.
    OccidentalRelating to the countries of the West.A native or inhabitant of the West.
    Occidentalistone who favors occidental culture
    OccipitalRelating to or situated in the back of the head.
    Occludedformal, technical formal, technical Dentistry Chemistry
    OccludentSomething that occludes; an occluder.Having the function of, involved in, or undergoing closure or occlusion;
    specifically designating the edges of the opercular plates of a barnacle
    which come into contact when the aperture is closed.
    OcclusalDentistry
    Occlusiveserving to occlude
    OccultSupernatural, mystical, or magical beliefs, practices, or phenomena.Of, involving, or relating to supernatural, mystical, or magical powers or
    phenomena.Medicine Cut off from view by interposing something.
    Occultismoccult theory or practice
    Occultistoccult theory or practice
    OccupationalRelating to a job or profession.
    Occupativeheld by occupation
    Occupied(of a building, seat, etc.) being used by someone.Busy and active.(of a place, especially a country) taken control of by military conquest or
    settlement.
    OccurrentActually occurring or observable, not potential or hypothetical.
    Ocean-Going(of a ship) designed to cross oceans.
    OceanianRelating to or characteristic of the islands of Oceania or their
    inhabitants.A native or inhabitant of the islands of Oceania.
    OceanicRelating to the ocean.
    Oceanographica science that deals with the oceans and includes the delimitation of their extent and depth, the physics and
    chemistry of their waters, marine biology, and the exploitation of their
    resources
    Oceanographicala science that deals with the oceans and includes the delimitation of their extent and depth, the physics and
    chemistry of their waters, marine biology, and the exploitation of their
    resources
    OcellarRelating to a simple eye or eyespot.
    Ocellated(of an animal) having eye-like markings.
    OcherAn earthy pigment containing ferric oxide, typically with clay, varying
    from light yellow to brown or red.
    Ocherousan earthy usually red or yellow and often impure iron ore used as a pigment
    Ocheryocherous
    Ochlocraticgovernment by the mob
    Ochlocraticalgovernment by the mob
    OchreAn earthy pigment containing ferric oxide, typically with clay, varying
    from light yellow to brown or red.
    Ochreousan earthy usually red or yellow and often impure iron ore used as a pigment
    OckerA boorish or aggressive person, especially an Australian man.
    OcreateBotany Ornithology
    OctadicOf or relating to an octad or octads. “octadic surface” noun Geometry a
    quartic surface having eight nodes which can be thought of as the
    intersections of three quadric surfaces.
    OctagonalHaving the shape or cross section of an octagon; eight-sided.
    Octahedralhaving eight plane faces
    OctalRelating to or using a system of numerical notation that has 8 rather than
    10 as a base.The octal system; octal notation.
    OctamerousBotany Zoology
    OctangularHaving eight angles.
    OctantalOf or relating to an octant; specifically recurring in each octant of the
    compass.
    Octastylemarked by columniation with eight columns across the front — compare distyle
    OctavalOf or relating to an octave; proceeding by octaves, or by eights.
    OctaveMusic A poem or stanza of eight lines; an octet.The eighth day after a church festival, inclusive of the day of the
    festival.Fencing
    OctennialRecurring every eight years.
    OctillionthEach of an octillion equal parts into which something is or may be divided.
    OctogenarianA person who is from 80 to 89 years old.
    OctonaryRelating to or based on the number eight.
    OctopodA cephalopod mollusk of the order Octopoda; an octopus.
    OctosyllabicHaving or written in lines that have eight syllables.
    OctupleConsisting of eight parts or things.Make or become eight times as numerous or as large.
    OctupledConsisting of eight parts or things.Make or become eight times as numerous or as large.
    OctupletEach of eight children born at one birth.
    OctuplingConsisting of eight parts or things.Make or become eight times as numerous or as large.
    OcularOf or connected with the eyes or vision.
    OculomotorRelating to the motion of the eye.
    OceloidOctachordalOctennially

    61 Words That Start With oD, oE, oF, oG, oH, oI, oK Adjectives

    OddDifferent from what is usual or expected; strange.(of whole numbers such as 3 and 5) having one left over as a remainder when
    divided by two.attributiveSeparated from a usual pair or set and therefore out of place or mismatched.
    OddballA strange or eccentric person.Strange; bizarre.
    Odd-JobA casual or isolated piece of work, especially one of a routine domestic or
    manual nature.
    Odds-On(especially of a horse) rated as most likely to win.
    OdiousExtremely unpleasant; repulsive.
    OdontoidA toothlike projection from the second cervical vertebra on which the first
    vertebra pivots.
    Odontophoroushaving an odontophore
    OdoriferousHaving or giving off a smell, especially an unpleasant or distinctive one.
    OdorlessHaving no odor.
    OdorousHaving or giving off a smell.
    Odourlessa quality of something that stimulates the olfactory organ
    Oecumenicecumenical
    OedipeanRelating to or reminiscent of the legend of Oedipus, characteristic of
    Oedipus; specifically (in early use) clever at guessing riddles; (now
    frequently) = “Oedipal”.
    OesophagealRelating to the esophagus.
    OffAway from the place in question; to or at a distance.So as to be removed or separated.Starting a journey or race; leaving.So as to bring to an end or be discontinued.(of an electrical appliance or power supply) not functioning or so as to
    cease to function.Having access to or possession of material goods or wealth to the extent
    specified.Moving away and often down from.Situated or leading in a direction away from (a main route or intersection)So as to be removed or separated from.attributivepredicativeattributiveBritish The half of the field (as divided lengthways through the pitch) toward
    which the batsman’s feet are pointed when standing to receive the ball.Kill; murder.
    OffbeatUnconventional; unusual.Music Any of the normally unaccented beats in a bar.
    Off-BroadwayDenoting or taking place in a class of theaters in New York City that are
    smaller than those in the Broadway theater district and typically stage
    less expensive or commercial productions.(in New York City) in a theater that is smaller than those in the Broadway
    theater district and typically stages less commercial productions.Off-Broadway theaters and productions collectively.
    OffencelessThat does not offend, unoffending, inoffensive; not causing offence or
    disgust. Formerly also
    OffendedResentful or annoyed, typically as a result of a perceived insult.
    OffendingCausing problems or displeasure.Relating to the committing of an illegal act or the breaking of a rule.
    OffensiveCausing someone to feel deeply hurt, upset, or angry.attributiveAn attacking military campaign.
    OfferableThat can or may be offered.
    OffhandUngraciously or offensively nonchalant or cool in manner.Without previous thought or consideration.
    OffhandedUngraciously or offensively nonchalant or cool in manner; offhand.
    OfficialRelating to an authority or public body and its duties, actions, and
    responsibilities.A person holding public office or having official duties, especially as a
    representative of an organization or government department.
    Officinal(of a herb or drug) standardly used in medicine.
    OfficiousAssertive of authority in an annoyingly domineering way, especially with
    regard to petty or trivial matters.
    OffishAloof or distant in manner; not friendly.
    Off-Key(of music or singing) not having the correct tone or pitch; out of tune.With incorrect tone or pitch.
    Off-LineNot controlled by or directly connected to a computer or external network.While not directly controlled by or connected to a computer or external
    network.
    Off-PuttingUnpleasant, disconcerting, or repellent.
    Off-RoadAway from a smooth road; on rough terrain.(of a vehicle or bicycle) designed for use over rough terrain.
    OffsettingA consideration or amount that diminishes or balances the effect of a
    contrary one.The amount or distance by which something is out of line.A side shoot from a plant serving for propagation.Architecture A bend in a pipe to carry it past an obstacle.often as modifierwith objectwith objectno object
    OffshoreSituated at sea some distance from the shore.Made, situated, or registered abroad, especially in order to take advantage
    of lower taxes or costs or less stringent regulation.At sea some distance from the shore.In a foreign country, especially in order to take advantage of lower taxes
    or costs or less stringent regulation.Relocate (a business or department) to a foreign country to take advantage
    of lower taxes or costs.
    Offside(especially in soccer or hockey) in a position where playing the ball or
    puck is not allowed, especially (in soccer) in the attacking half ahead of
    the ball and having fewer than two defenders nearer the goal line at the
    moment the ball is played.(especially in soccer or hockey) occupying or taking place in a position
    where playing the ball or puck is not allowed, especially (in soccer) in
    the attacking half ahead of the ball and having fewer than two defenders
    nearer the goal line at the moment the ball is played.The fact of being offside in soccer and other sports.usually the off side
    Off-SiteTaking place or situated away from a particular place or site.Away from a particular place or site.
    Off-The-CuffWithout preparation.
    Off-The-Peg(of clothes) ready-made; off the rack.
    Off-The-ShelfNot designed or made to order but taken from existing stock or supplies.
    Off-WhiteA white color with a gray or yellowish tinge.
    OftenFrequently; many times.
    OgygianOf or relating to the mythological island of Ogygia in Homer’s Odyssey
    where Calypso lived.
    Ohmicthe practical meter-kilogram-second unit of electric resistance equal to
    the resistance of a circuit in which a potential difference of one volt
    produces a current of one ampere
    OiledLubricated, coated, or impregnated with oil.
    OilierContaining oil.(of a person or their behavior) unpleasantly smooth and ingratiating.
    OiliestContaining oil.(of a person or their behavior) unpleasantly smooth and ingratiating.
    OilyContaining oil.(of a person or their behavior) unpleasantly smooth and ingratiating.
    OkayUsed to express assent, agreement, or acceptance.Satisfactory but not exceptionally or especially good.In a satisfactory manner or to a satisfactory extent.An authorization or approval.Sanction or give approval to.Oklahoma (in official postal use).
    Ok’DUsed to express assent, agreement, or acceptance.Satisfactory but not exceptionally or especially good.In a satisfactory manner or to a satisfactory extent.An authorization or approval.Sanction or give approval to.Oklahoma (in official postal use).
    OkeSouth African
    OdontalgicOdontologicalOecumenical
    OestrousOff-CentreOff-Off-Broadway
    OffscreenOff-StreetOgreish
    Oil-FiredOkey-Doke

    49 Adjectives Beginning With OL

    OldHaving lived for a long time; no longer young.attributivein combination informal
    OldenRelating to former times.
    OlderHaving lived for a long time; no longer young.attributivein combination informal
    OldestHaving lived for a long time; no longer young.attributivein combination informal
    OldfangledCharacterized by adherence to what is old; old-fashioned.
    Old-FashionedIn or according to styles or types no longer current or common; not modern.A cocktail consisting chiefly of whiskey, bitters, water, and sugar.
    Old-FogeyishOf, relating to, or resembling an old fogey; likely to appeal to an old
    fogey.
    Oldishsomewhat old or elderly
    Old-Maidishspinstersense 3
    Old-RoseA double-flowered rose of a variety or hybrid evolved before the
    development of the hybrid tea rose.A shade of grayish or purplish pink.
    Old-TimeRelating to or characteristic of the past; long-standing.
    Old-WomanishPrim or fussy.
    Old-WorldBelonging to or associated with former times, especially when considered
    quaint and attractive.
    Oleaceousof or relating to the Oleaceae
    OleaginousRich in, covered with, or producing oil; oily or greasy.Exaggeratedly and distastefully complimentary; obsequious.
    Oleica monounsaturated fatty acid C18H34O2 obtained from natural fats and oils
    OleophilicHaving an affinity for oils or oily materials; readily absorbing oil.
    Olfactiveolfactory
    OlfactoryRelating to the sense of smell.
    OlidSmelling extremely unpleasant.
    Oligarchicof, relating to, or based on an oligarchy
    Oligarchicalof, relating to, or based on an oligarchy
    OligoceneRelating to or denoting the third epoch of the Tertiary period, between the
    Eocene and Miocene epochs.the Oligocene
    OligochaeteAn annelid worm of the class Oligochaeta, such as an earthworm.
    Oligopolistica market situation in which each of a few producers affects but does not
    control the market
    Oligopsonistica market situation in which each of a few buyers exerts a disproportionate
    influence on the market
    Oligotrophic(especially of a lake) relatively low in plant nutrients and containing
    abundant oxygen in the deeper parts.
    OlivaceousOf a dusky yellowish green color; olive green.
    OlivaryRelating to or denoting each of the pair of oval bodies of nerve tissue on
    the medulla oblongata of the brain.
    OliveA small oval fruit with a hard pit and bitter flesh, green when unripe and
    brownish black when ripe, used as food and as a source of oil.A metal ring or fitting which is tightened under a threaded nut to form a
    seal, as in a compression joint.Grayish-green, like an unripe olive.
    OlympianAssociated with Mount Olympus in northeastern Greece, or with the Greek
    gods whose home was traditionally held to be there.attributiveAny of the twelve Greek gods regarded as living on Olympus.A competitor in the Olympic Games.
    OlympicRelating to the ancient city of Olympia or the Olympic Games.
    Omentala fold of peritoneum connecting or supporting abdominal structures (such as
    the stomach and liver)
    OminousGiving the impression that something bad or unpleasant is going to happen;
    threatening; inauspicious.
    Omissiblethat may be omitted
    Omissiveleaving out
    OmnibusA volume containing several novels or other items previously published
    separately. dated Comprising several items.
    Omnicompetentable to handle any situation
    OmnidirectionalReceiving signals from or transmitting in all directions.
    OmnifariousComprising or relating to all sorts or varieties.
    OmnificAll-creating; making or doing all things.
    Omnipotent(of a deity) having unlimited power; able to do anything.God.
    OmnipresentWidely or constantly encountered; common or widespread.
    OmniscientKnowing everything.
    Omnivorous(of an animal or person) feeding on food of both plant and animal origin.
    Old-EstablishedOlde-WorldeOld-Fogyish
    Omophagic

    49 Adjectives That Start With OM, ON, OO

    OnagraceousOf or relating to the family Onagraceae, of which Onagra (now Oenothera)
    was the type genus, and which includes plants such as the evening
    primroses, willowherbs, and fuchsias.
    Onanisticmasturbation
    OnceOn one occasion or for one time only.At some time in the past; formerly.As soon as; when.
    OncogenicCausing development of a tumor or tumors.
    OncomingApproaching; moving toward.The fact of being about to happen in the near future.
    OneReferring to a person or thing previously mentioned or easily identified.A person of a specified kind.third person singular
    One-Armedslot machinesense 2
    One-DimensionalHaving or relating to a single dimension.
    One-EyedHaving only one eye.US vulgar slang Narrow-minded, prejudiced; having a blinkered outlook.British
    One-HandedHaving or using only one hand.With only one hand.
    One-HorseDrawn by or using a single horse.
    OneiricRelating to dreams or dreaming.
    OneirocriticalRelating to, practising, or expert in, the interpretation of dreams.
    One-ManInvolving, done, or operated by only one person.
    One-On-OneA face-to-face encounter.
    One-Piece(especially of an article of clothing) made or consisting of a single piece.An article of clothing made or consisting of a single piece.
    Onerous(of a task, duty, or responsibility) involving an amount of effort and
    difficulty that is oppressively burdensome.
    One-SidedUnfairly giving or dealing with only one side of a contentious issue or
    question; biased or partial.
    One-TimeFormer.Relating to a single occasion.
    One-To-OneA face-to-face encounter.
    One-TrackHaving only one track of rails.Concentrated on, preoccupied with, or capable of only one subject or line
    of thought; obsessional; especially in “one-track mind”.
    One-UpHaving a psychological advantage over someone.Do better than (someone)
    One-WayMoving or allowing movement in one direction only.
    OngoingContinuing; still in progress.
    Onionya widely cultivated Asian herb (Allium cepa) of the lily family with pungent edible bulbs
    On-Lineconnected to, served by, or available through a system and especially a
    computer or telecommunications system (such as the Internet)
    OnlyAnd no one or nothing more besides; solely or exclusively.No longer ago than.with infinitiveAlone of its or their kind; single or solitary.Except that; but for the fact that.
    OnomasticRelating to the study of the history and origin of proper names.
    OnomatopoeicUsing or relating to onomatopoeia.
    Onomatopoeticthe naming of a thing or action by a vocal imitation of the sound associated with it (such as buzz, hiss)
    OnshoreSituated or occurring on land.On land; ashore.Transfer (a business or department that was moved overseas) back to the
    country from which it was originally relocated.
    Onside(especially in soccer or hockey) occupying a position on the field where
    playing the ball or puck is allowed; not offside.(especially in soccer or hockey) in a position on the field where playing
    the ball or puck is allowed; not offside. informal
    On-SiteTaking place or situated at a particular place or site.At a particular place or site.
    Onstage(in a theater) on or onto the stage and so visible to the audience.(in a theater) taking place on the stage and so visible to the audience.
    On-StreamIn or into production or operation.Performed or occurring as part of production or operation.
    On-The-SpotWithout any delay; immediately.At the scene of an action or event.
    Ontogeneticof, relating to, or appearing in the course of ontogeny
    Ontogenicontogenetic
    OntologicalRelating to the branch of metaphysics dealing with the nature of being.Showing the relations between the concepts and categories in a subject area
    or domain.
    OnwardIn a continuing forward direction; ahead.Going further rather than coming to an end or halt; moving forward.
    Onymousbearing a name
    OogamousRelating to or denoting reproduction by the union of mobile male and
    immobile female gametes.
    OogeneticOf or relating to oogenesis.
    Oolitica rock consisting of small round grains usually of calcium carbonate
    cemented together
    Ooziercontaining or composed of ooze
    Ooziestcontaining or composed of ooze
    Oozingno object, with adverbial of directionwith objectThe sluggish flow of a fluid.An infusion of oak bark or other vegetable matter, used in tanning.Wet mud or slime, especially that found at the bottom of a river, lake, or
    sea.
    Oozycontaining or composed of ooze

    73 Adjectives Starting With OP

    OpaqueNot able to be seen through; not transparent.An opaque thing or substance.
    OpenAllowing access, passage, or a view through an empty space; not closed or
    blocked up.attributiveWith the outer edges or sides drawn away from each other; unfolded.predicativeFreely available or accessible; offered without restriction.(of a person) frank and communicative; not given to deception or
    concealment.(of a question, case, or decision) not finally settled; still admitting of
    debate.Music Phonetics (of an electrical circuit) having a break in the conducting path.Move or adjust (a door or window) so as to leave a space allowing access
    and view.Unfold or be unfolded; spread out.Make officially ready for customers, visitors, or business.Formally establish or begin (a new business or enterprise)Make (something) present, available, or accessible.no objectBreak the conducting path of (an electrical circuit)the openAn accidental break in the conducting path for an electric current.
    Openedhaving no enclosing or confining barrier
    Open-Endorganized to allow for contingencies
    Open-FacedHaving a frank or ingenuous expression.(of a watch, especially a pocket watch) having no cover other than the
    glass.
    Open-Heartedcandidly straightforward
    Operativeproducing an appropriate effect
    Ophiologicalof or relating to ophiology
    Ophthalmologicala branch of medical science dealing with the structure, functions, and
    diseases of the eye
    OpinionativeHolding obstinately to one’s own opinion; opinionated. rare
    Opisthognathoushaving retreating jaws
    Opportunistictaking advantage of opportunities as they arise
    OpticRelating to the eye or vision.A lens or other optical component in an optical instrument. archaic, humorous
    OpalescentOpen-ChainOpen-Hearth
    OpalineOpen-DoorOpening
    OpeOpen-EndedOpen-Letter
    Open-AirOpen-EyedOpen-Minded
    Open-And-ShutOpen-FieldOpen-Mouthed
    OpencastOpen-HandedOpen-Plan
    Open-ShopOperculateOphitic
    OperableOperculatedOphthalmic
    OperantOperoseOphthalmoscopic
    OperaticOphidianOphthalmoscopical
    OperatingOphiolatrousOpinionated
    OperationalOphiologicOppidan
    OpponentOppositeOppugnant
    OpportuneOppositionalOpsonic
    OpportunistOppositiveOptative
    OpposableOppressedOptical
    OpposedOppressiveOptimal
    OpposingOpprobriousOptimistic
    OptimumOptionalOptometrically
    OpulentOpuscule

    88 Words That Start With OR Adjectives

    OracularRelating to an oracle.
    OralBy word of mouth; spoken rather than written.Relating to the mouth.often orals
    OrangeA town in southern France, on the Rhône River, home of the ancestors of the
    Dutch royal house.A city in southwestern California, southeast of Los Angeles in an
    agricultural area; population 136,392 (est. 2008).Relating to the Orange Order.A round juicy citrus fruit with a tough bright reddish-yellow rind.A bright reddish-yellow color like that of the skin of a ripe orange.Reddish yellow.
    OratoricalRelating to the art or practice of public speaking.
    Orbiculartechnical technical
    OrbiculateOrbicular.
    OrbitalRelating to an orbit or orbits.Each of the actual or potential patterns of electron density that may be
    formed in an atom or molecule by one or more electrons, and that can be
    represented as a wave function.
    Orcadiana native or inhabitant of the Orkney Islands
    OrchestralWritten for an orchestra to play.
    OrchestratedArrange or score (music) for orchestral performance.Arrange or direct the elements of (a situation) to produce a desired
    effect, especially surreptitiously.
    OrchidaceousRelating to or denoting plants of the orchid family (Orchidaceae).
    Orchiticrare, historical Of or relating to orchitis; affected by orchitis.
    OrdainableCapable of being ordained; that may be ordained.
    OrdainedMake (someone) a priest or minister; confer holy orders on.Order or decree (something) officially.
    OrderedThe arrangement or disposition of people or things in relation to each
    other according to a particular sequence, pattern, or method.An authoritative command, direction, or instruction.A particular social, political, or economic system.in singularBiology Any of the five classical styles of architecture (Doric, Ionic, Corinthian,
    Tuscan, and Composite) based on the proportions of columns, amount of
    decoration, etc.Military Mathematics reporting verbwith objectwith object
    OrderlyNeatly and methodically arranged.An attendant in a hospital responsible for the nonmedical care of patients
    and the maintenance of order and cleanliness.A soldier who carries out orders or performs minor tasks for an officer.
    OrdinalChristian Church Relating to a thing’s position in a series.
    OrdinaryWith no special or distinctive features; normal.(especially of a judge or bishop) exercising authority by virtue of office
    and not by delegation.the ordinaryBritish usually OrdinaryHeraldry archaic mainly North American
    Ordinate(in a system of coordinates) the y-coordinate, representing the distance
    from a point to the horizontal or x-axis measured parallel to the vertical
    or y-axis.
    OrdovicianRelating to or denoting the second period of the Paleozoic era, between the
    Cambrian and Silurian periods.the Ordovician
    OrdurousOf the nature of ordure; filthy.
    OrecticOf or concerning desire or appetite.
    OrganicRelating to or derived from living matter.(of food or farming methods) produced or involving production without the
    use of chemical fertilizers, pesticides, or other artificial agents.Physiology Denoting a relation between elements of something such that they fit
    together harmoniously as necessary parts of a whole.
    OrganicismThe doctrine that everything in nature has an organic basis or is part of
    an organic whole.The use or advocacy of literary or artistic forms in which the parts are
    connected or coordinated in the whole.
    OrganisationalRelating to an organization or the way it is set up.Relating to the action of organizing something.
    OrganizationalRelating to an organization or the way it is set up.Relating to the action of organizing something.
    OrganizedArranged in a systematic way, especially on a large scale.
    OrganolepticActing on, or involving the use of, the sense organs.
    Organometallic(of a compound) containing a metal atom bonded to an organic group or
    groups.
    OrgasmicRelating to orgasm.
    OrgiasticOf or resembling an orgy.
    OrgulousHaughty.
    Orientthe OrientThe special luster of a pearl of the finest quality. literary with objectAdjust or tailor (something) to specified circumstances or needs.
    OrientalOf, from, or characteristic of Asia, especially East Asia.(of a pearl or other jewel) orient.A person of East Asian descent.
    Orientedthe OrientThe special luster of a pearl of the finest quality. literary with objectAdjust or tailor (something) to specified circumstances or needs.
    Orientingthe OrientThe special luster of a pearl of the finest quality. literary with objectAdjust or tailor (something) to specified circumstances or needs.
    OriginalPresent or existing from the beginning; first or earliest.Created directly and personally by a particular artist; not a copy or
    imitation.Not dependent on other people’s ideas; inventive and unusual.Something serving as a model or basis for imitations or copies.An eccentric or unusual person.
    OrinasalOf, relating to, or connecting the mouth and the nose; (Phonetics)
    pronounced with the oral and nasal passages open.
    OrnamentalServing or intended as an ornament; decorative.A plant or tree grown for its attractive appearance.
    OrnamentedA thing used to make something look more attractive but usually having no
    practical purpose, especially a small object such as a figurine.Make (something) look more attractive by adding decorative items.
    OrnateMade in an intricate shape or decorated with complex patterns.
    OrneryNorth American
    OrnithicOf, relating to, or characteristic of birds; avian.
    OrnithischianRelating to or denoting herbivorous dinosaurs of an order distinguished by
    having a pelvic structure resembling that of birds.An ornithischian dinosaur.
    OrnithoidResembling a bird in structure; like that of a bird; (of fossil eggs)
    having shells like those of birds’ eggs.
    OrologicalOf or relating to orology.
    Orotund(of the voice or phrasing) full, round, and imposing.
    OrphanA child whose parents are dead.Printing Make (a person or animal) an orphan.
    OrphanedA child whose parents are dead.Printing Make (a person or animal) an orphan.
    OrpheanRelating to or characteristic of the poet Orpheus, especially in being
    melodious or entrancing.
    OrphicOf or concerning Orpheus or Orphism.
    OrthoStraight; rectangular; upright.Chemistry Chemistry
    Orthochromatic(of black-and-white photographic film) sensitive to all visible light
    except red. Orthochromatic film can therefore be handled in red light in
    the darkroom but does not produce black-and-white tones that correspond
    very closely to the colors seen by the eye.
    OrthodonticsThe treatment of irregularities in the teeth (especially of alignment and
    occlusion) and jaws, including the use of braces.
    Orthodox(of a person or their views, especially religious or political ones, or
    other beliefs or practices) conforming to what is generally or
    traditionally accepted as right or true; established and approved.(of a thing) of the ordinary or usual type; normal.usually Orthodoxusually Orthodox
    OrthogenicBiology Leading to or promoting good health; (specifically in Psychology) concerned
    with or relating to the use of remedial procedures in the education of
    children with learning difficulties.
    Orthognathous(especially of a person) having a jaw that does not project or recede, so
    that the facial profile is nearly vertical.
    OrthogonalOf or involving right angles; at right angles.Statistics
    OrthopaedicRelating to the branch of medicine dealing with the correction of
    deformities of bones or muscles.
    OrthopedicRelating to the branch of medicine dealing with the correction of
    deformities of bones or muscles.
    OrthophyricCharacterized by or designating a rock texture in which there is a
    groundmass of randomly oriented, short, stout feldspar crystals of
    rectangular or square cross-section.
    OrthorhombicOf or denoting a crystal system or three-dimensional geometric arrangement
    having three unequal axes at right angles.
    OrthoscopicHaving or producing normal vision; yielding an image free from optical
    distortion; specifically of binocular vision
    OrthostichousHaving leaves arranged in orthostichies; characterized by such an
    arrangement.
    OrthotoneHaving its own accent as an independent word; accented; specifically said
    of a word ordinarily unaccented (as an enclitic or proclitic) when it
    retains or takes an independent accent.An orthotone word.
    OrthotropicBotany Engineering
    Orthotropous(of a plant ovule) having the nucleus straight, i.e., not inverted, so that
    the micropyle is at the end opposite the base.
    OrdinaireOrientatedOrogenetic
    OrganisableOrientatingOrthodontic
    OrganismalOrigenisticOrthogenetic
    OrganismicOriginativeOrthographic
    OrganizableOrnithologicalOrthopedical
    OrogastricOrobanchaceousOrthophosphoric
    OrthopterousOrthoptic
    Adjectives That Start With O

    42 Adjectives Beginning With OS, OT

    OscanAn extinct Italic language of southern Italy, related to Umbrian and
    surviving in inscriptions mainly of the 4th to 1st centuries BC.Relating to Oscan.
    OscillatingMove or swing back and forth at a regular speed.Physics
    OscineRelating to or denoting passerine birds of a large division that includes
    the songbirds.A bird of the oscine division.
    Oscularhumorous Zoology
    Osculatorythe act of kissing
    OsmanliRelating to the Ottoman empire or to the Turkish dynasty of Osman I (Othman
    I).A Turk, especially of the period of the Ottoman empire.
    OsmicRelating to odors or the sense of smell.
    OsseousConsisting of or turned into bone; ossified.
    OssicularOf or relating to an ossicle or ossicles.
    Ossiferous(of a cave or stratum) containing or yielding deposits of bone.
    OstealOf, relating to, or characteristic of bone.
    OstensibleStated or appearing to be true, but not necessarily so.
    OsteoarthritisDegeneration of joint cartilage and the underlying bone, most common from
    middle age onward. It causes pain and stiffness, especially in the hip,
    knee, and thumb joints.
    Osteogeneticproducing bone
    OsteoidResembling bone in appearance or structure.The unmineralized organic component of bone.
    OsteoplasticSurgery Medicine Physiology
    Ostracodana subclass of crustacea comprising small active mostly freshwater forms
    having the body enclosed in a bivalve shell composed of right and left
    valves, the body segmentation obscured, the abdomen rudimentary, and only
    seven pairs of appendages
    OtherDenoting a person or thing that is different or distinct from one already
    mentioned or known about.Further; additional.A person or thing that is different or distinct from one already mentioned
    or known about.A further or additional person or thing of the type aleady mentioned.the OtherView or treat (a person or group of people) as intrinsically different from
    and alien to oneself.
    OtherworldlyRelating to an imaginary or spiritual world.
    OticRelating to the ear.
    OtioseServing no practical purpose or result.
    OttomanA low upholstered seat, or footstool, without a back or arms that typically
    serves also as a box, with the seat hinged to form a lid.A heavy ribbed fabric made from silk and either cotton or wool, typically
    used for coats. historical historical A Turk, especially of the period of the Ottoman Empire.
    OscillatoryOsmousOsteological
    OscitantOssianicOsteopathic
    OsculantOssieOsteophytic
    OsieredOssifiedOstracodous
    OsmiousOstensiveOstrogothic
    OsmoticOstentatiousOthergates

    51 Adjectives That Start With OU

    OutMoving or appearing to move away from a particular place, especially one
    that is enclosed or hidden.Situated far or at a particular distance from somewhere.Away from home.So as to be revealed or known.At or to an end.(of a light or fire) so as to be extinguished or no longer burning.(of a jury) considering its verdict in secrecy.Indicating a specified distance away from the goal line or finishing line.(of a party, politician, etc.) not in office.Through to the outside.Not at home or at one’s place of work.Revealed or made public.No longer alight; extinguished.(of a book, recording, or other product) published or made available.Not concealing one’s sexuality or gender identity.At an end.In a state of unconsciousness.Mistaken; in error.Cricket Baseball informal Baseball the outsReveal the sexual or gender identity of (a person). dated West Indian archaic, literary
    Out-And-OutIn every respect; absolute; without question.
    OutbackThe remote and usually uninhabited inland regions of Australia.
    OutboardSituated on, towards, or near the outside of a ship or aircraft.(of an electronic accessory) in a separate container from the device with
    which it is used.Toward the outside of a ship or aircraft.An outboard motor.
    OutboundTraveling away from a particular place, especially on the first leg of a
    return journey.Away from a particular place, especially on the first leg of a return
    journey.
    Outbredwith objectno object
    OutcastA person who has been rejected by society or a social group.Rejected or cast out.
    Outcaste(in Hindu society) a person who has no caste or has been expelled from a
    caste.Cause (someone) to lose one’s caste.
    OutclassedBe far superior to.
    OutdatedOut of date; obsolete.
    OutdoneBe more successful than.
    OutdoorDone, situated, or used out of doors.
    OutdoorsyOf, associated with, or fond of the outdoors.
    OuterOutside; external.
    OutermostFarthest from the center.The one that is farthest from the center.
    OutfittedA set of clothes worn together, typically for a particular occasion or
    purpose.Provide (someone) with a set of clothes.
    OutflowingSomething that flows out.
    OutgoingFriendly and socially confident.attributiveoutgoings
    OutlandRemote or distant territory.Remote; distant.
    OutlandishLooking or sounding bizarre or unfamiliar. archaic
    OutlawA person who has broken the law, especially one who remains at large or is
    a fugitive.Ban or make illegal.
    OutlawedMade illegal; banned.
    OutlinedA line or set of lines enclosing or indicating the shape of an object in a
    sketch or diagram.A general description or plan giving the essential features of something
    but not the detail.Draw, trace, or define the outer edge or shape of (something)Give a summary of (something)
    OutlyingSituated far from a center; remote.
    OutmodedOld-fashioned.
    OutmostFarthest away.
    Out-Of-Bounds(in sports) outside the regular playing area.
    Out-Of-DateOld-fashioned.
    Out-Of-Dooroutdoor
    Out-Of-FashionUnpopular and not considered to be attractive at the time in question.
    Out-Of-PlaceNot in the proper position; disarranged.
    Out-Of-PocketHaving lost money in a transaction.
    Out-Of-Print(of a book) no longer available from the publisher.
    Out-Of-Stock(of goods) unavailable for immediate sale in a store.
    Out-Of-The-Way(of a place) remote or secluded.Dealt with or finished.usually with negative
    Out-Of-TownSituated, originating from, or taking place outside a town or city.
    Out-Of-WorkUnemployed.
    OutragedAn extremely strong reaction of anger, shock, or indignation.Arouse fierce anger, shock, or indignation in (someone)
    OutrageousShockingly bad or excessive.Very bold, unusual, and startling.
    OutremerA name applied to the medieval French crusader states, including Armenia,
    Antioch, Tripoli, and Jerusalem.
    OutrightAltogether; completely.Immediately.Open and direct; not concealed.
    OutsideThe external side or surface of something.The external appearance of someone or something.Situated on or near the exterior or external surface of something.Not belonging to or coming from within a particular group.Highest possible; greatest; maximum.Situated or moving beyond the boundaries or confines of.Beyond the limits or scope of.Not within the boundaries or confines of a place.
    OutsizeExceptionally large.An exceptionally large person or thing, especially a garment made to
    measurements larger than the standard.
    OutsizedExceptionally large.An exceptionally large person or thing, especially a garment made to
    measurements larger than the standard.
    OutspokenFrank in stating one’s opinions, especially if they are critical or
    controversial.
    OutspreadFully extended or expanded.Spread out.
    OutstandingExceptionally good.Remaining to be paid, done, or dealt with.
    Outstretched(especially of a hand or arm) extended or stretched out.
    OutwardOf, on, or from the outside.Going out or away from a place.Away from the center or a particular point; toward the outside.
    Outward-Bound(of a ship or passenger) going away from home or point of origin.
    OutwornOut of date.

    128 Adjectives Starting With OV

    OvalHaving a rounded and slightly elongated outline or shape like that of an
    egg.A body, object, or design with an oval shape or outline.
    OvarianRelating to an ovary or the ovaries.
    OverallTaking everything into account.In all parts; taken as a whole.North American
    OverarmDone with the hand or arm passing above the level of the shoulder.With the hand or arm passing above the level of the shoulder.
    OverawedImpress (someone) so much that they become silent or inhibited.
    OverboldExcessively bold.
    OverbusyExcessively busy.
    Overcast(of the sky or weather) marked by a covering of gray clouds; dull.(in sewing) edged with stitching to prevent fraying.Clouds covering a large part of the sky.Cover with clouds or shade.Stitch over (an unfinished edge) to prevent fraying.
    OvercomeSucceed in dealing with (a problem or difficulty)
    OverdueNot having arrived, happened, or been done by the expected time.Having been needed for some time.
    OverfarToo far; to too great a distance, extent, or degree.
    OverfondHaving too great an affection or liking for someone or something.
    OverfreeExcessively free; too generous; too frank or uninhibited.
    OverfullContaining an excessive amount of something.
    Overhandmainly North American Done with the palm of the hand downward or inward.With the hand or arm passing above the level of the shoulder.
    OverheadAbove the level of the head; in the sky.Situated above the level of the head.(of a driving mechanism) above the object driven.attributiveAn overhead cost or expense.A transparency designed for use with an overhead projector.An overhead compartment.
    Overloadedto load (something or someone) to excess
    OverlongToo long.For too long.
    OvermuchToo much; excessively.Too great in amount; excessive.An excessive amount.
    Overproofcontaining more alcohol than proof spirit
    OverrunSpread over or occupy (a place) in large numbers.Continue beyond or above an expected or allowed time or cost.An instance of something exceeding an expected or allowed time or cost.The movement or extension of something beyond an allotted or particular
    position or space.The movement of a vehicle at a speed greater than is imparted by the engine.
    OverseaIn or to a foreign country, especially one across the sea.From, to, or relating to a foreign country, especially one across the sea.
    OvertDone or shown openly; plainly or readily apparent, not secret or hidden.
    Over-The-CounterBy ordinary retail purchase, with no need for a prescription or license.
    Overwroughtextremely excited
    OviformEgg-shaped.
    Ovoid(of a solid or a three-dimensional surface) egg-shaped.An ovoid body or surface.
    OvateOverbearingOvercorrect
    Oven-ReadyOverblownOvercredulous
    OverOverburdenedOvercritical
    OverabundantOverburdensomeOvercurious
    OveractiveOvercarefulOverdelicate
    OverambitiousOvercautiousOverdone
    OverdressedOverexcitedOverglaze
    OvereagerOverfedOvergreat
    OverearnestOverflowingOvergreedy
    OveremotionalOverforwardOverground
    OverenthusiasticOverfraughtOvergrown
    OverexcitableOvergenerousOverhanded
    OverhangingOverkindOverlooking
    OverhappyOverladenOverloud
    OverhastyOverlandOverlying
    OverheatedOverlappingOvermerry
    OverindulgentOverlargeOvermodest
    OverjoyedOverlookedOverneat
    OverniceOverprotectiveOverripe
    OvernightOverproudOverscrupulous
    OveroptimisticOverrankOverseas
    OverpoweredOverrashOversensitive
    OverpoweringOverreachingOversewn
    OverpricedOverridingOversexed
    OvershotOverstayedOversuspicious
    OversimplifiedOverstrongOvertedious
    OversizeOverstrungOverthrown
    OversizedOverstuffedOverturned
    OverspreadingOversubscribedOverviolent
    OverstatedOversubtleOverweary
    OverweeningOviferousOvidian
    OverweightOvineOvular
    OverwhelmedOviparousOverzealous
    OverwhelmingOvoviviparous

    19 Adjectives Beginning With OW, OY, OZ

    OwedHave an obligation to pay or repay (something, especially money) in return
    for something received.
    Owing(of money) yet to be paid.
    OwlishLike an owl, especially in acting or appearing wise or solemn.
    Owlishlyresembling or suggesting an owl
    Owllikelike that of an owl
    OwnUsed with a possessive to emphasize that someone or something belongs or
    relates to the person or thing mentioned.Something that belongs to the person or thing mentioned.with object formal US
    OwnedUsed with a possessive to emphasize that someone or something belongs or
    relates to the person or thing mentioned.Something that belongs to the person or thing mentioned.with object formal US
    Ownerlesshaving no owner
    Owner-Occupied(of a house or apartment) used as a dwelling by the owner.
    Oxalica poisonous strong acid (COOH)2 or H2C2O4 that occurs in various plants (such as spinach) as oxalates and is used
    especially as a bleaching or cleaning agent and as a chemical intermediate
    OxbloodThe blood of an ox.A deep red, tinged with brown, resembling the colour of oxblood.Of the colour of oxblood; specifically of a deep red colour tinged with
    brown.
    Ox-EyedHaving eyes resembling those of an ox; especially having large round or
    protuberant eyes.
    OxidisedCombine or become combined chemically with oxygen.
    Oxidizableto combine with oxygen
    OxidizedCombine or become combined chemically with oxygen.
    OxonianRelating to Oxford, England, or Oxford University.A native or inhabitant of Oxford, England.
    OxygenatedSupplied, treated, or enriched with oxygen.
    Oxytocichastening childbirth
    OzoniferousContaining or producing ozone.

    Conclusion

    Read:  Describing Words for Purpose - Examples of Adjectives

    There are many great adjectives that start with the letter O. Some of our favorites include:

    outstanding – above average in quality or performance, organized – arranged in a systematic way, original – not copied or derived from something else, outgoing – friendly and sociable.

    These are just a few of the many wonderful adjectives that start with O. We hope you’ll take the time to explore them all!

    Positive Words That Start With

    ABCDEFGHIJKLMNOPQRSTUVWXYZ

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