90 Adjectives That Start With “O” (2023)

90 Adjectives That Start With “O” (1)

    Adjectives That Start with O


    Background: Tolchik / iStock / Getty Images Plus


    Used under Getty Images license

Few things in life offer such perfection as the letter “O.” It’s a perfect circle, an outstanding shape that forms some of the most optimal adjectives you’ll ever see. Adjectives are that special ingredient that help nouns become more opulent, ostentatious, or just plain ordinary. Adjectives that start with “O” give you an overflowing amount of options for your everyday vocabulary.

Positive Adjectives That Start With “O”

“O” adjectives offer a whole spectrum of positivity for you to play with. Are you having an okay time or an outstanding time? With the right positive adjective, your jewelry can be ornate or opalescent, and you can be more optimistic and outgoing.

obligingready to do favors; helpful; courteous; accommodatingfriendly, amiable, hospitable
observantquick to notice or perceivealert, watchful, careful
odds-onhaving a strong chance of succeeding or winningfavorite, predictable, likely
okay (or OK)correct; meeting standards; proceeding normallysatisfactory, acceptable
omnicompetentable to deal with all matters or situationsmultitalented, capable, efficient
one-of-a-kinduniqueoriginal, distinct, rare
opalescentdisplaying a variety of colors, like an opaliridescent, prismatic, multi-colored
open-heartednot reserved; kindly or benevolentcompassionate, friendly, generous
open-mindedunbiased; consider new ideasreceptive, approachable, understanding
opportunehappening or done at the right time; seasonable; well-timed; timelyadvantageous, auspicious, felicitous
optimalbest; most favorableexcellent, greatest, matchless
optimistichaving the tendency to take the most hopeful or cheerful view of matters or to expect the best outcomepositive, hopeful, idealistic
optimumbest; most favorableideal, greatest, superlative
opulentvery wealthy or rich; characterized by abundanceextravagant, luxurious, lavish
orderlyorganized in a neat, tidy mannersystematic, clean, well-kept
originativehaving the power to produce or create somethingcreative, gifted, innovative
ornateelaborate; embellishedbaroque, elegant, lavish
orotund(of voice or speech) strong, full, rich, and clearbombastic, resonant, sonorous
outgoingfriendly, sociableextroverted, warm, gregarious
out-of-this-worldsuperb, extraordinarymarvelous, heavenly, wonderful
outstandingprominent; distinguished; excellent; marked by superiority or distinctionexceptional, impressive, magnificent
overjoyedextremely happy; delightedjoyful, euphoric, jubilant


Negative Adjectives That Start With “O”

Unfortunately, not all moments call for positivity. Sometimes, you need a negative adjective starting with “O” to describe any objectionable offenses, obscene occasions, or odious occurrences.

objectionabledisagreeable; offensiveunpleasant, deplorable, repulsive
obliqueslanting; indirectly stated or expressed; evasivebackhanded, vague, sideways
obliterateddestroyed utterlyeliminated, annihilated, erased
obliviousnot aware of or concerned; unmindful; forgetfulunconscious, unaware, ignorant
obnoxiousvery unpleasantoffensive, detestable, hateful
obsceneoffensive to one's feelings, or to prevailing notions of modesty or decency; lewdindecent, bawdy, crude
obscurenot clear; uncertainconfusing, enigmatic, ambiguous
obstinatestubbornly adhering to one’s opinioninflexible, dogmatic, headstrong
obstructiveblocking, hindering, or interrupting; deliberately causing delaysunhelpful, difficult, unaccommodating
obtrusivenoticeable in an intrusive or unwelcome wayobvious, meddlesome, intrusive
obtuseslow to understand or perceive; dull or insensitiveblunt, dense, imperceptive
odiousrepulsive; revoltinghorrible, loathsome, vile
offensiveunpleasant to the senses; disgustingrepugnant, irritating, objectonable
officiousaggressive in offering unwanted services or help; asserting authority in a domineering waybossy, meddlesome, pushy
ominousportending harm or evilforeboding, inauspicious, menacing
onerousinvolving a great amount of effort that can feel oppressively burdensomearduous, exhausting, laborious
opinionatedstubborn or conceited in regard to the merits of one’s opinionsdogmatic, cocky, bullheaded
opportunistictaking advantage of the situation for personal benefitconniving, wily, devious
oppressiveunjust treatment; cruel; tyrannicaloverwhelming, burdensome, inhuman
ostentatiouscharacterized by or given to pretentious or conspicuous show in an attempt to impress othersgaudy, highfalutin, egotistic
overbearingoverpowering or domineeringbossy, imperious, oppressive
overblownoverinflated; excessivepretentious, disproportionate, turgid
overloadedloaded with an excessive burdenoverworked, strained, stressed
oversimplifiedsimplified to the point of misrepresenting factssimplistic, unnuanced, distorted


Neutral Adjectives That Start With “O”

Of course, most of life isn’t just positive or negative. Most people, places, and objects just exist, but that doesn’t mean they should go without some good descriptors. From odd cookies to omnivorous bears, “O” adjectives offer plenty of optional ornaments for your nouns.

obesefat; stoutcorpulent, plump, portly
obsoleteno longer in use or practice; discardedantiquated, dated, archaic
obviousclear; apparentunderstandable, overt, noticeable
occasionalof irregular occurrence; happening now and thensporadic, intermittent, infrequent
oddnot usual or ordinary; singular; peculiar; strangedifferent, unusual, bizarre
offbeatunusualstrange, unconventional, idiosyncratic
oilyof, like, consisting of, or containing oil; smooth or unctuous in character or mannerslippery, buttery, slick
oldernot young; lived for a long timeelder, senior
old-fashionedbehind the times; not currentantiquated, dated, outmoded
omnipotenthaving unlimited power or authority; all-powerfulalmighty, godlike, unrestricted
omniscienthaving infinite knowledge; knowing all thingsall-know, all-seeing, pansophical
omnivorouseating both plants and animals; taking in everythingpredatory, ravenous, gluttonous
opaquenot letting light pass through; not transparent or translucentcloudy, hazy, murky
operableusable; can be usedfeasible, doable, practicable
operativefunctioning; effectiveactive, usable, functional
opposing/opposedset against; placed opposite, in balance or contrast; contending within speech or actionresisting, antagonistic, conflicting
opposable(of thumbs) capable of touching other digits on handprehensile
oppositedifferent in every way; exactly contraryantithetical, unlike, contradictory
optionalnot required; left to your own choicenoncompulsory, nonobligatory, discretional
oralspoken by the mouthvocal, articulate, phonated
orangecolor between red and yellowred-yellow, carrot
ordinarynot special; normal; usualeveryday, typical, common
originalhaving to do with an origin; fresh, new, novelinitial, creative, earliest
ornamentaldecorativeshowy, dressy, embellishing
orthodoxconforming to the usual beliefs or established doctrines, as in religion, politics, etc.traditional, conventional, conservative
outlandishbizarre; unfamiliar; weirdstrange, eccentric, peculiar


“O” Adjectives To Describe a Person

Plenty of the adjectives above offer some excellent, obvious descriptors for people, but it doesn’t hurt to arm yourself with plenty of official “O” adjectives to describe a person.

oafishclumsy; unculturedblundering, bumbling, graceless
obedientobeying or willing to obey; submissivewell-behaved, compliant, faithful
obeisantshowing respectdeferential, reverent, dutiful
obsessiveconsuming; being consumedcompulsive, controlling, fanatical
occupiedactive or busyengrossed, engaged, employed
ornerystubborn; unpleasant in disposition or tempercranky, grumpy, ill-tempered
outcastrejected or discarded; cast outunwanted, unaccepted, undesirable
outdoorsyextremely fond of outdoor lifenature-loving
outrageoushaving the nature of, involving, or doing great injury or wrong; very offensive or shockingdisgraceful, scandalous, startling
outspokenexpress opinions directly; bluntcandid, forthright, frank
overachievingperforming better or accomplishing more than expectedoutperforming, intellectual, phenomenal
overboldexcessively boldblatant, conspicuous, shameless
overconfidentextremely confidentbrash, careless, cocky
overcriticalextremely criticalhypercritical, nit-picking, disparaging
overextendedexhausted; stressed outfatigued, overworked, burdened
overprotectiveexcessively protectivevigilant, shielding, restrictive
overqualifiedhaving more experience, training, or education than required for a job or positionworldly, scholarly, well-read
overwroughtextremely excited or agitatedfrantic, emotional, worked-up


Example Sentences for Adjectives That Start With “O”

Knowing all these adjectives that start with “O” is just half the battle. You have to learn how to actually use them until you feel overconfident and overqualified.

  1. My open-minded friend was willing to try just about anything at least once.
  2. I had the onerous task of alphabetizing all of our spices and condiments.
  3. She made a one-of-a-kind mug in her ceramics class.
  4. Despite his offbeat personality, he was extremely relatable and easy to get along with.
  5. He was ashamed of the glass cup that had gotten increasingly opaque from sitting on his desk for so long.
  6. After weeks of being under construction, the elevator was finally operable.
  7. The obnoxious combination of screaming kids and someone practicing the bagpipes made it hard for him to get any rest.
  8. He was worried about the ominous work email that simply read, “Do you have time to talk?”
  9. Aside from the occasional pepperoni pizza, his diet was mostly vegetarian.
  10. The oppressive heat made it hard for her to want to do anything other than read in an air-conditioned cafe.
  11. The French fries were oily, but that’s exactly how he liked them.
  12. Our outgoing friend was always talking to strangers and making friends with store workers.
  13. This seemed like an opportune moment to remind the kids not to push and shove each other when the bell rang.
  14. The final exam involved a written test and an oral presentation.
  15. Whenever he felt himself losing hope, he talked to his optimistic friend.
  16. She appreciated the fine artistry and ornate details in the statue.
  17. The camp ranger taught us about the omnivorous bears that loved to eat meat, roots, and marshmallows.
  18. The overjoyed team learnedthey had two days off this week.
  19. The whole class did such an outstanding job on the test that she told them they’d have pizza and ice cream to celebrate.
  20. They spent two hours discussing the optimum amount of salsa for tortilla chips.


Oh! Even More “O” Words

With your brain overloaded with adjectives starting with “O,” you can expand your vocabulary further with other parts of speech. Learning more words that start with “O” will improve your writing and conversational abilities, and it just might help you get the winning score in your word games.

  • Nouns That Start With “O”
  • Verbs That Start With “O”
  • “O” Words for Word Games
Top Articles
Latest Posts
Article information

Author: Moshe Kshlerin

Last Updated: 06/08/2023

Views: 6030

Rating: 4.7 / 5 (57 voted)

Reviews: 88% of readers found this page helpful

Author information

Name: Moshe Kshlerin

Birthday: 1994-01-25

Address: Suite 609 315 Lupita Unions, Ronnieburgh, MI 62697

Phone: +2424755286529

Job: District Education Designer

Hobby: Yoga, Gunsmithing, Singing, 3D printing, Nordic skating, Soapmaking, Juggling

Introduction: My name is Moshe Kshlerin, I am a gleaming, attractive, outstanding, pleasant, delightful, outstanding, famous person who loves writing and wants to share my knowledge and understanding with you.