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:
- 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.
78 Adjectives That Start With OA, OB
|Oafish||Stupid, uncultured, or clumsy.|
|Oak||A 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.
|Oaken||Made of timber from the oak tree.|
|Oared||a long pole with a broad blade at one end used for propelling or steering a|
|Oaten||Made with or containing oats.|
|Obbligato||An instrumental part, typically distinctive in effect, which is integral to|
a piece of music and should not be omitted in performance.
|Obconic||In the form of an inverted cone.|
|Obconical||In the form of an inverted cone.|
|Obcordate||(of a leaf) in the shape of a heart with the pointed end at the base.|
|Obdurate||Stubbornly refusing to change one’s opinion or course of action.|
|Obedient||Complying or willing to comply with orders or requests; submissive to|
|Obeliscal||Of the nature of or resembling an obelisk; of or relating to an obelisk.|
|Obese||Very 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
|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|
|Obligate||Bind or compel (someone), especially legally or morally.US Restricted to a particular function or mode of life.|
|Obligated||Bind or compel (someone), especially legally or morally.US Restricted to a particular function or mode of life.|
|Obligato||An instrumental part, typically distinctive in effect, which is integral to|
a piece of music and should not be omitted in performance.
|Obligatory||Required by a legal, moral, or other rule; compulsory.|
|Obliged||Make (someone) legally or morally bound to an action or course of action.|
|Obliging||Willing to do a service or kindness; helpful.|
|Oblique||Neither 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
|Obliterate||Destroy utterly; wipe out.|
|Oblivious||Not aware of or not concerned about what is happening around one.|
|Oblong||An object or flat figure in an elongated rectangle or oval shape.Having an elongated shape, as a rectangle or an oval.|
|Obovate||(of a leaf) ovate with the narrower end at the base.|
|Obovoid||Obovate in cross-section; inversely ovoid.|
|Obscene||(of the portrayal or description of sexual matters) offensive or disgusting|
by accepted standards of morality and decency.
|Obscurant||A 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.
|Obscurantist||A person who deliberately prevents the facts or full details of something|
from becoming known.Deliberately preventing the facts or full details of something from
|Obscure||Not discovered or known about; uncertain.Keep from being seen; conceal.|
|Obsequent||Compliant, yielding, obedient; deferential, servile.Of a stream, stream valley, or drainage pattern|
|Obsequious||Obedient or attentive to an excessive or servile degree.|
|Observable||Able to be noticed or perceived; discernible.|
|Observant||Quick 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.|
|Observed||Notice or perceive (something) and register it as being significant.reporting verbFulfill or comply with (a social, legal, ethical, or religious obligation)|
|Observing||Notice or perceive (something) and register it as being significant.reporting verbFulfill or comply with (a social, legal, ethical, or religious obligation)|
|Obsessed||Preoccupy or fill the mind of (someone) continually, intrusively, and to a|
|Obsessive||Of the nature of an obsession.A person who is affected by an obsession.|
|Obsolete||No longer produced or used; out of date.Biology Cause (a product or idea) to be or become obsolete by replacing it with|
|Obstetric||Relating to childbirth and the processes associated with it.|
|Obstinate||Stubbornly refusing to change one’s opinion or chosen course of action,|
despite attempts to persuade one to do so.
|Obstreperous||Noisy and difficult to control.|
|Obstructed||Block (an opening, path, road, etc.); be or get in the way of.|
|Obstructive||Causing a blockage or obstruction.Causing or tending to cause deliberate difficulties and delays.|
|Obstruent||A fricative or plosive speech sound.|
|Obtainable||Able 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.
|Obtrusive||Noticeable or prominent in an unwelcome or intrusive way.|
|Obtundent||A 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.
|Obtuse||Annoyingly insensitive or slow to understand.(of an angle) more than 90° and less than 180°Not sharp-pointed or sharp-edged; blunt.|
|Obumbrate||To overshadow; to shade, darken; to obscure. (literal and figurative).|
|Obverse||The 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|
|Obviating||Remove (a need or difficulty)|
|Obvious||Easily 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.
56 Adjectives Starting With OC
|Occasional||Occurring, appearing, or done infrequently and irregularly.|
|Occidental||Relating to the countries of the West.A native or inhabitant of the West.|
|Occidentalist||one who favors occidental culture|
|Occipital||Relating to or situated in the back of the head.|
|Occluded||formal, technical formal, technical Dentistry Chemistry|
|Occludent||Something 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.
|Occlusive||serving to occlude|
|Occult||Supernatural, 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.
|Occultism||occult theory or practice|
|Occultist||occult theory or practice|
|Occupational||Relating to a job or profession.|
|Occupative||held 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|
|Occurrent||Actually occurring or observable, not potential or hypothetical.|
|Ocean-Going||(of a ship) designed to cross oceans.|
|Oceanian||Relating to or characteristic of the islands of Oceania or their|
inhabitants.A native or inhabitant of the islands of Oceania.
|Oceanic||Relating to the ocean.|
|Oceanographic||a 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
|Oceanographical||a 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
|Ocellar||Relating to a simple eye or eyespot.|
|Ocellated||(of an animal) having eye-like markings.|
|Ocher||An earthy pigment containing ferric oxide, typically with clay, varying|
from light yellow to brown or red.
|Ocherous||an earthy usually red or yellow and often impure iron ore used as a pigment|
|Ochlocratic||government by the mob|
|Ochlocratical||government by the mob|
|Ochre||An earthy pigment containing ferric oxide, typically with clay, varying|
from light yellow to brown or red.
|Ochreous||an earthy usually red or yellow and often impure iron ore used as a pigment|
|Ocker||A boorish or aggressive person, especially an Australian man.|
|Octadic||Of 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.
|Octagonal||Having the shape or cross section of an octagon; eight-sided.|
|Octahedral||having eight plane faces|
|Octal||Relating to or using a system of numerical notation that has 8 rather than|
10 as a base.The octal system; octal notation.
|Octangular||Having eight angles.|
|Octantal||Of or relating to an octant; specifically recurring in each octant of the|
|Octastyle||marked by columniation with eight columns across the front — compare distyle|
|Octaval||Of or relating to an octave; proceeding by octaves, or by eights.|
|Octave||Music A poem or stanza of eight lines; an octet.The eighth day after a church festival, inclusive of the day of the|
|Octennial||Recurring every eight years.|
|Octillionth||Each of an octillion equal parts into which something is or may be divided.|
|Octogenarian||A person who is from 80 to 89 years old.|
|Octonary||Relating to or based on the number eight.|
|Octopod||A cephalopod mollusk of the order Octopoda; an octopus.|
|Octosyllabic||Having or written in lines that have eight syllables.|
|Octuple||Consisting of eight parts or things.Make or become eight times as numerous or as large.|
|Octupled||Consisting of eight parts or things.Make or become eight times as numerous or as large.|
|Octuplet||Each of eight children born at one birth.|
|Octupling||Consisting of eight parts or things.Make or become eight times as numerous or as large.|
|Ocular||Of or connected with the eyes or vision.|
|Oculomotor||Relating to the motion of the eye.|
61 Words That Start With oD, oE, oF, oG, oH, oI, oK Adjectives
|Odd||Different 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.
|Oddball||A strange or eccentric person.Strange; bizarre.|
|Odd-Job||A casual or isolated piece of work, especially one of a routine domestic or|
|Odds-On||(especially of a horse) rated as most likely to win.|
|Odious||Extremely unpleasant; repulsive.|
|Odontoid||A toothlike projection from the second cervical vertebra on which the first|
|Odontophorous||having an odontophore|
|Odoriferous||Having or giving off a smell, especially an unpleasant or distinctive one.|
|Odorless||Having no odor.|
|Odorous||Having or giving off a smell.|
|Odourless||a quality of something that stimulates the olfactory organ|
|Oedipean||Relating to or reminiscent of the legend of Oedipus, characteristic of|
Oedipus; specifically (in early use) clever at guessing riddles; (now
frequently) = “Oedipal”.
|Oesophageal||Relating to the esophagus.|
|Off||Away 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.
|Offbeat||Unconventional; unusual.Music Any of the normally unaccented beats in a bar.|
|Off-Broadway||Denoting 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.
|Offenceless||That does not offend, unoffending, inoffensive; not causing offence or|
disgust. Formerly also
|Offended||Resentful or annoyed, typically as a result of a perceived insult.|
|Offending||Causing problems or displeasure.Relating to the committing of an illegal act or the breaking of a rule.|
|Offensive||Causing someone to feel deeply hurt, upset, or angry.attributiveAn attacking military campaign.|
|Offerable||That can or may be offered.|
|Offhand||Ungraciously or offensively nonchalant or cool in manner.Without previous thought or consideration.|
|Offhanded||Ungraciously or offensively nonchalant or cool in manner; offhand.|
|Official||Relating 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.|
|Officious||Assertive of authority in an annoyingly domineering way, especially with|
regard to petty or trivial matters.
|Offish||Aloof 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-Line||Not controlled by or directly connected to a computer or external network.While not directly controlled by or connected to a computer or external|
|Off-Putting||Unpleasant, disconcerting, or repellent.|
|Off-Road||Away from a smooth road; on rough terrain.(of a vehicle or bicycle) designed for use over rough terrain.|
|Offsetting||A 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
|Offshore||Situated 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-Site||Taking place or situated away from a particular place or site.Away from a particular place or site.|
|Off-The-Peg||(of clothes) ready-made; off the rack.|
|Off-The-Shelf||Not designed or made to order but taken from existing stock or supplies.|
|Off-White||A white color with a gray or yellowish tinge.|
|Often||Frequently; many times.|
|Ogygian||Of or relating to the mythological island of Ogygia in Homer’s Odyssey|
where Calypso lived.
|Ohmic||the 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
|Oiled||Lubricated, coated, or impregnated with oil.|
|Oilier||Containing oil.(of a person or their behavior) unpleasantly smooth and ingratiating.|
|Oiliest||Containing oil.(of a person or their behavior) unpleasantly smooth and ingratiating.|
|Oily||Containing oil.(of a person or their behavior) unpleasantly smooth and ingratiating.|
|Okay||Used 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’D||Used 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).|
49 Adjectives Beginning With OL
|Old||Having lived for a long time; no longer young.attributivein combination informal|
|Olden||Relating to former times.|
|Older||Having lived for a long time; no longer young.attributivein combination informal|
|Oldest||Having lived for a long time; no longer young.attributivein combination informal|
|Oldfangled||Characterized by adherence to what is old; old-fashioned.|
|Old-Fashioned||In or according to styles or types no longer current or common; not modern.A cocktail consisting chiefly of whiskey, bitters, water, and sugar.|
|Old-Fogeyish||Of, relating to, or resembling an old fogey; likely to appeal to an old|
|Oldish||somewhat old or elderly|
|Old-Rose||A 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-Time||Relating to or characteristic of the past; long-standing.|
|Old-Womanish||Prim or fussy.|
|Old-World||Belonging to or associated with former times, especially when considered|
quaint and attractive.
|Oleaceous||of or relating to the Oleaceae|
|Oleaginous||Rich in, covered with, or producing oil; oily or greasy.Exaggeratedly and distastefully complimentary; obsequious.|
|Oleic||a monounsaturated fatty acid C18H34O2 obtained from natural fats and oils|
|Oleophilic||Having an affinity for oils or oily materials; readily absorbing oil.|
|Olfactory||Relating to the sense of smell.|
|Olid||Smelling extremely unpleasant.|
|Oligarchic||of, relating to, or based on an oligarchy|
|Oligarchical||of, relating to, or based on an oligarchy|
|Oligocene||Relating to or denoting the third epoch of the Tertiary period, between the|
Eocene and Miocene epochs.the Oligocene
|Oligochaete||An annelid worm of the class Oligochaeta, such as an earthworm.|
|Oligopolistic||a market situation in which each of a few producers affects but does not|
control the market
|Oligopsonistic||a 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.
|Olivaceous||Of a dusky yellowish green color; olive green.|
|Olivary||Relating to or denoting each of the pair of oval bodies of nerve tissue on|
the medulla oblongata of the brain.
|Olive||A 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.
|Olympian||Associated 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.
|Olympic||Relating to the ancient city of Olympia or the Olympic Games.|
|Omental||a fold of peritoneum connecting or supporting abdominal structures (such as|
the stomach and liver)
|Ominous||Giving the impression that something bad or unpleasant is going to happen;|
|Omissible||that may be omitted|
|Omnibus||A volume containing several novels or other items previously published|
separately. dated Comprising several items.
|Omnicompetent||able to handle any situation|
|Omnidirectional||Receiving signals from or transmitting in all directions.|
|Omnifarious||Comprising or relating to all sorts or varieties.|
|Omnific||All-creating; making or doing all things.|
|Omnipotent||(of a deity) having unlimited power; able to do anything.God.|
|Omnipresent||Widely or constantly encountered; common or widespread.|
|Omnivorous||(of an animal or person) feeding on food of both plant and animal origin.|
49 Adjectives That Start With OM, ON, OO
|Onagraceous||Of 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.
|Once||On one occasion or for one time only.At some time in the past; formerly.As soon as; when.|
|Oncogenic||Causing development of a tumor or tumors.|
|Oncoming||Approaching; moving toward.The fact of being about to happen in the near future.|
|One||Referring to a person or thing previously mentioned or easily identified.A person of a specified kind.third person singular|
|One-Armed||slot machinesense 2|
|One-Dimensional||Having or relating to a single dimension.|
|One-Eyed||Having only one eye.US vulgar slang Narrow-minded, prejudiced; having a blinkered outlook.British|
|One-Handed||Having or using only one hand.With only one hand.|
|One-Horse||Drawn by or using a single horse.|
|Oneiric||Relating to dreams or dreaming.|
|Oneirocritical||Relating to, practising, or expert in, the interpretation of dreams.|
|One-Man||Involving, done, or operated by only one person.|
|One-On-One||A 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-Sided||Unfairly giving or dealing with only one side of a contentious issue or|
question; biased or partial.
|One-Time||Former.Relating to a single occasion.|
|One-To-One||A face-to-face encounter.|
|One-Track||Having 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-Up||Having a psychological advantage over someone.Do better than (someone)|
|One-Way||Moving or allowing movement in one direction only.|
|Ongoing||Continuing; still in progress.|
|Oniony||a widely cultivated Asian herb (Allium cepa) of the lily family with pungent edible bulbs|
|On-Line||connected to, served by, or available through a system and especially a|
computer or telecommunications system (such as the Internet)
|Only||And 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.|
|Onomastic||Relating to the study of the history and origin of proper names.|
|Onomatopoeic||Using or relating to onomatopoeia.|
|Onomatopoetic||the naming of a thing or action by a vocal imitation of the sound associated with it (such as buzz, hiss)|
|Onshore||Situated 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-Site||Taking 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-Stream||In or into production or operation.Performed or occurring as part of production or operation.|
|On-The-Spot||Without any delay; immediately.At the scene of an action or event.|
|Ontogenetic||of, relating to, or appearing in the course of ontogeny|
|Ontological||Relating to the branch of metaphysics dealing with the nature of being.Showing the relations between the concepts and categories in a subject area|
|Onward||In a continuing forward direction; ahead.Going further rather than coming to an end or halt; moving forward.|
|Onymous||bearing a name|
|Oogamous||Relating to or denoting reproduction by the union of mobile male and|
immobile female gametes.
|Oogenetic||Of or relating to oogenesis.|
|Oolitic||a rock consisting of small round grains usually of calcium carbonate|
|Oozier||containing or composed of ooze|
|Ooziest||containing or composed of ooze|
|Oozing||no 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|
|Oozy||containing or composed of ooze|
73 Adjectives Starting With OP
|Opaque||Not able to be seen through; not transparent.An opaque thing or substance.|
|Open||Allowing 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.
|Opened||having no enclosing or confining barrier|
|Open-End||organized to allow for contingencies|
|Open-Faced||Having a frank or ingenuous expression.(of a watch, especially a pocket watch) having no cover other than the|
|Operative||producing an appropriate effect|
|Ophiological||of or relating to ophiology|
|Ophthalmological||a branch of medical science dealing with the structure, functions, and|
diseases of the eye
|Opinionative||Holding obstinately to one’s own opinion; opinionated. rare|
|Opisthognathous||having retreating jaws|
|Opportunistic||taking advantage of opportunities as they arise|
|Optic||Relating to the eye or vision.A lens or other optical component in an optical instrument. archaic, humorous|
88 Words That Start With OR Adjectives
|Oracular||Relating to an oracle.|
|Oral||By word of mouth; spoken rather than written.Relating to the mouth.often orals|
|Orange||A 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.
|Oratorical||Relating to the art or practice of public speaking.|
|Orbital||Relating 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.
|Orcadian||a native or inhabitant of the Orkney Islands|
|Orchestral||Written for an orchestra to play.|
|Orchestrated||Arrange or score (music) for orchestral performance.Arrange or direct the elements of (a situation) to produce a desired|
effect, especially surreptitiously.
|Orchidaceous||Relating to or denoting plants of the orchid family (Orchidaceae).|
|Orchitic||rare, historical Of or relating to orchitis; affected by orchitis.|
|Ordainable||Capable of being ordained; that may be ordained.|
|Ordained||Make (someone) a priest or minister; confer holy orders on.Order or decree (something) officially.|
|Ordered||The 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
|Orderly||Neatly 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.
|Ordinal||Christian Church Relating to a thing’s position in a series.|
|Ordinary||With 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
|Ordovician||Relating to or denoting the second period of the Paleozoic era, between the|
Cambrian and Silurian periods.the Ordovician
|Ordurous||Of the nature of ordure; filthy.|
|Orectic||Of or concerning desire or appetite.|
|Organic||Relating 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.
|Organicism||The 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.
|Organisational||Relating to an organization or the way it is set up.Relating to the action of organizing something.|
|Organizational||Relating to an organization or the way it is set up.Relating to the action of organizing something.|
|Organized||Arranged in a systematic way, especially on a large scale.|
|Organoleptic||Acting on, or involving the use of, the sense organs.|
|Organometallic||(of a compound) containing a metal atom bonded to an organic group or|
|Orgasmic||Relating to orgasm.|
|Orgiastic||Of or resembling an orgy.|
|Orient||the OrientThe special luster of a pearl of the finest quality. literary with objectAdjust or tailor (something) to specified circumstances or needs.|
|Oriental||Of, from, or characteristic of Asia, especially East Asia.(of a pearl or other jewel) orient.A person of East Asian descent.|
|Oriented||the OrientThe special luster of a pearl of the finest quality. literary with objectAdjust or tailor (something) to specified circumstances or needs.|
|Orienting||the OrientThe special luster of a pearl of the finest quality. literary with objectAdjust or tailor (something) to specified circumstances or needs.|
|Original||Present 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.
|Orinasal||Of, relating to, or connecting the mouth and the nose; (Phonetics)|
pronounced with the oral and nasal passages open.
|Ornamental||Serving or intended as an ornament; decorative.A plant or tree grown for its attractive appearance.|
|Ornamented||A 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.
|Ornate||Made in an intricate shape or decorated with complex patterns.|
|Ornithic||Of, relating to, or characteristic of birds; avian.|
|Ornithischian||Relating to or denoting herbivorous dinosaurs of an order distinguished by|
having a pelvic structure resembling that of birds.An ornithischian dinosaur.
|Ornithoid||Resembling a bird in structure; like that of a bird; (of fossil eggs)|
having shells like those of birds’ eggs.
|Orological||Of or relating to orology.|
|Orotund||(of the voice or phrasing) full, round, and imposing.|
|Orphan||A child whose parents are dead.Printing Make (a person or animal) an orphan.|
|Orphaned||A child whose parents are dead.Printing Make (a person or animal) an orphan.|
|Orphean||Relating to or characteristic of the poet Orpheus, especially in being|
melodious or entrancing.
|Orphic||Of or concerning Orpheus or Orphism.|
|Ortho||Straight; 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.
|Orthodontics||The 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
|Orthogenic||Biology 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.
|Orthogonal||Of or involving right angles; at right angles.Statistics|
|Orthopaedic||Relating to the branch of medicine dealing with the correction of|
deformities of bones or muscles.
|Orthopedic||Relating to the branch of medicine dealing with the correction of|
deformities of bones or muscles.
|Orthophyric||Characterized 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.
|Orthorhombic||Of or denoting a crystal system or three-dimensional geometric arrangement|
having three unequal axes at right angles.
|Orthoscopic||Having or producing normal vision; yielding an image free from optical|
distortion; specifically of binocular vision
|Orthostichous||Having leaves arranged in orthostichies; characterized by such an|
|Orthotone||Having 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.
|Orthotropous||(of a plant ovule) having the nucleus straight, i.e., not inverted, so that|
the micropyle is at the end opposite the base.
42 Adjectives Beginning With OS, OT
|Oscan||An extinct Italic language of southern Italy, related to Umbrian and|
surviving in inscriptions mainly of the 4th to 1st centuries BC.Relating to Oscan.
|Oscillating||Move or swing back and forth at a regular speed.Physics|
|Oscine||Relating to or denoting passerine birds of a large division that includes|
the songbirds.A bird of the oscine division.
|Osculatory||the act of kissing|
|Osmanli||Relating to the Ottoman empire or to the Turkish dynasty of Osman I (Othman|
I).A Turk, especially of the period of the Ottoman empire.
|Osmic||Relating to odors or the sense of smell.|
|Osseous||Consisting of or turned into bone; ossified.|
|Ossicular||Of or relating to an ossicle or ossicles.|
|Ossiferous||(of a cave or stratum) containing or yielding deposits of bone.|
|Osteal||Of, relating to, or characteristic of bone.|
|Ostensible||Stated or appearing to be true, but not necessarily so.|
|Osteoarthritis||Degeneration 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.
|Osteoid||Resembling bone in appearance or structure.The unmineralized organic component of bone.|
|Osteoplastic||Surgery Medicine Physiology|
|Ostracodan||a 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
|Other||Denoting 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.
|Otherworldly||Relating to an imaginary or spiritual world.|
|Otic||Relating to the ear.|
|Otiose||Serving no practical purpose or result.|
|Ottoman||A 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.
51 Adjectives That Start With OU
|Out||Moving 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-Out||In every respect; absolute; without question.|
|Outback||The remote and usually uninhabited inland regions of Australia.|
|Outboard||Situated 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.
|Outbound||Traveling 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
|Outbred||with objectno object|
|Outcast||A 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.
|Outclassed||Be far superior to.|
|Outdated||Out of date; obsolete.|
|Outdone||Be more successful than.|
|Outdoor||Done, situated, or used out of doors.|
|Outdoorsy||Of, associated with, or fond of the outdoors.|
|Outermost||Farthest from the center.The one that is farthest from the center.|
|Outfitted||A set of clothes worn together, typically for a particular occasion or|
purpose.Provide (someone) with a set of clothes.
|Outflowing||Something that flows out.|
|Outgoing||Friendly and socially confident.attributiveoutgoings|
|Outland||Remote or distant territory.Remote; distant.|
|Outlandish||Looking or sounding bizarre or unfamiliar. archaic|
|Outlaw||A person who has broken the law, especially one who remains at large or is|
a fugitive.Ban or make illegal.
|Outlawed||Made illegal; banned.|
|Outlined||A 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)
|Outlying||Situated far from a center; remote.|
|Out-Of-Bounds||(in sports) outside the regular playing area.|
|Out-Of-Fashion||Unpopular and not considered to be attractive at the time in question.|
|Out-Of-Place||Not in the proper position; disarranged.|
|Out-Of-Pocket||Having 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-Town||Situated, originating from, or taking place outside a town or city.|
|Outraged||An extremely strong reaction of anger, shock, or indignation.Arouse fierce anger, shock, or indignation in (someone)|
|Outrageous||Shockingly bad or excessive.Very bold, unusual, and startling.|
|Outremer||A name applied to the medieval French crusader states, including Armenia,|
Antioch, Tripoli, and Jerusalem.
|Outright||Altogether; completely.Immediately.Open and direct; not concealed.|
|Outside||The 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.|
|Outsize||Exceptionally large.An exceptionally large person or thing, especially a garment made to|
measurements larger than the standard.
|Outsized||Exceptionally large.An exceptionally large person or thing, especially a garment made to|
measurements larger than the standard.
|Outspoken||Frank in stating one’s opinions, especially if they are critical or|
|Outspread||Fully extended or expanded.Spread out.|
|Outstanding||Exceptionally good.Remaining to be paid, done, or dealt with.|
|Outstretched||(especially of a hand or arm) extended or stretched out.|
|Outward||Of, 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.|
|Outworn||Out of date.|
128 Adjectives Starting With OV
|Oval||Having a rounded and slightly elongated outline or shape like that of an|
egg.A body, object, or design with an oval shape or outline.
|Ovarian||Relating to an ovary or the ovaries.|
|Overall||Taking everything into account.In all parts; taken as a whole.North American|
|Overarm||Done with the hand or arm passing above the level of the shoulder.With the hand or arm passing above the level of the shoulder.|
|Overawed||Impress (someone) so much that they become silent or inhibited.|
|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.|
|Overcome||Succeed in dealing with (a problem or difficulty)|
|Overdue||Not having arrived, happened, or been done by the expected time.Having been needed for some time.|
|Overfar||Too far; to too great a distance, extent, or degree.|
|Overfond||Having too great an affection or liking for someone or something.|
|Overfree||Excessively free; too generous; too frank or uninhibited.|
|Overfull||Containing an excessive amount of something.|
|Overhand||mainly North American Done with the palm of the hand downward or inward.With the hand or arm passing above the level of the shoulder.|
|Overhead||Above 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.|
|Overloaded||to load (something or someone) to excess|
|Overlong||Too long.For too long.|
|Overmuch||Too much; excessively.Too great in amount; excessive.An excessive amount.|
|Overproof||containing more alcohol than proof spirit|
|Overrun||Spread 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.
|Oversea||In or to a foreign country, especially one across the sea.From, to, or relating to a foreign country, especially one across the sea.|
|Overt||Done or shown openly; plainly or readily apparent, not secret or hidden.|
|Over-The-Counter||By ordinary retail purchase, with no need for a prescription or license.|
|Ovoid||(of a solid or a three-dimensional surface) egg-shaped.An ovoid body or surface.|
19 Adjectives Beginning With OW, OY, OZ
|Owed||Have an obligation to pay or repay (something, especially money) in return|
for something received.
|Owing||(of money) yet to be paid.|
|Owlish||Like an owl, especially in acting or appearing wise or solemn.|
|Owlishly||resembling or suggesting an owl|
|Owllike||like that of an owl|
|Own||Used 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
|Owned||Used 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
|Ownerless||having no owner|
|Owner-Occupied||(of a house or apartment) used as a dwelling by the owner.|
|Oxalic||a 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
|Oxblood||The 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|
|Ox-Eyed||Having eyes resembling those of an ox; especially having large round or|
|Oxidised||Combine or become combined chemically with oxygen.|
|Oxidizable||to combine with oxygen|
|Oxidized||Combine or become combined chemically with oxygen.|
|Oxonian||Relating to Oxford, England, or Oxford University.A native or inhabitant of Oxford, England.|
|Oxygenated||Supplied, treated, or enriched with oxygen.|
|Ozoniferous||Containing or producing ozone.|
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!