Words That Start with O
There are 1,958 words that start with O on Word.ws, from 2 to 15 letters. The most common length is 8 letters (277 words). The words used most often are of, on, or, one and out.
Meanings from Wiktionary. Not an official Scrabble, Words With Friends or Wordle word list.
2-letter words that start with O
- ob4n. A halfpenny.
- od3n. A hypothetical force or natural power, which was supposed by Carl...
- oe2n. A grandchild.
- of5prep. Since, from (a given time, earlier state etc.).
- oh5interj. Expression of surprise.
- oi2interj. Said to get someone's attention; hey.
- om4n. A sacred, mystical syllable used in prayer and meditation.
- on2adj. In the state of being active, functioning or operating.
- oo2n. Any of four Hawaiian birds of the genus Moho, formerly classed with the...
- op4n. An amateur radio operator.
- or2conj. Connects at least two alternative words, phrases, clauses, sentences...
- os2n. Synonym of bone.
- ot2n. The name of the Cyrillic script letter Ѿ / ѿ.
- ou2n. A probably extinct species of Hawaiian honeycreeper, Psittirostra...
- ow5interj. Synonym of ouch (“cry of pain”).
- ox9n. An adult castrated male of cattle (B. taurus), especially when used as...
- oy5interj. An exclamation typically expressing mild frustration or expressing...
3-letter words that start with O
- oak7n. A deciduous tree with distinctive deeply lobed leaves, acorns, and...
- oar3n. A type of lever used to propel a boat, having a flat blade at one end...
- oat3n. Widely cultivated cereal grass, typically Avena sativa.
- oba5n. A king of a Yoruba polity.
- obe5n. A particular subdivision of ancient Laconia.
- obi5n. A sash worn with a kimono.
- obs5n. Police observation.
- och8interj. General interjection of confirmation, affirmation, and often...
- oda4n. A room within a harem.
- odd5adj. Differing from what is usual, ordinary or expected.
- ode4n. A short poetical composition proper to be set to music or sung; a lyric...
- off9adv. In a direction away from the speaker or other reference point.
- oft6adv. Often; frequently; not rarely.
- ohm8n. In the International System of Units, the derived unit of electrical...
- oil3n. Liquid fat.
- old4adj. Of an object, concept, relationship, etc., having existed for a...
- ole3interj. An interjection used to stir up excitement.
- one3pron. One thing (among a group of others); one member of a group.
- oni3n. A Japanese evil spirit or demon.
- ono3adj. Good-tasting, delicious.
- oof6interj. A sound mimicking the loss of air, as if someone's solar plexus had...
- ooh6interj. An expression of surprise.
- oop5interj. Used to acknowledge a small mistake or accident.
- oot3pron. Anything.
- opa5n. Grandfather, grandpa.
- opp7n. An opponent; an enemy; the opposition.
- ops5n. Operations.
- opt5v. To choose; select.
- ora3n. A unit of money among the Anglo-Saxons.
- orb5n. A spherical body; a sphere, especially one of the celestial spheres; a...
- orc5n. A mythical evil monstrous humanoid creature, usually quite aggressive...
- ord4n. A point.
- ore3n. Rock or other material that contains valuable or utilitarian materials...
- oss3v. To set about, or intend be inclined to set about (doing something).
- our3det. Belonging to us, excluding the person(s) being addressed (exclusive...
- out3adv. Away from the inside or centre.
- owe6v. To be under an obligation to give something back to someone or to...
- owl6n. Any of various birds of prey of the order Strigiformes, families...
- own6adj. Belonging to; possessed; acquired and designated by; proper to...
- oxy13adj. Containing one or more oxygen atoms.
4-letter words that start with O
- oaks8n. A stakes race in which entry is restricted to 3-year-old fillies.
- oath7n. A solemn pledge or promise that invokes a deity, a ruler, or another...
- oats4n. A mass of oat plants (genus Avena, especially Avena sativa).
- obey9v. To do as ordered by (a person, institution etc), to act according to...
- odds6n. The ratio of the probability of an event happening to that of it not...
- odor5n. Any smell, whether fragrant or offensive.
- ogre5n. A large, grotesque, brutish humanoid monster, typically marked by great...
- oily7adj. Covered with or containing oil.
- okey11n. A Turkish game in which players attempt to collect certain groups of...
- olds5n. One's parents.
- omar6n. A glacial erratic piece of (typically smooth) dark siliceous greywacke...
- omen6n. Something which portends or is perceived to portend either a good or...
- omer6n. A former small Hebrew unit of dry volume equal to about 2.3 L or 2.1...
- omit6v. To leave out or exclude.
- omni6n. A person or animal who is not vegan; one with no particular dietary...
- once6adv. One and only one time.
- ones4n. A senior or first team (as opposed to a reserves team).
- only7adj. Alone in a category.
- onto4prep. Arriving upon or on top of (speaking of a physical or metaphorical...
- onus4n. A legal obligation.
- onyx14n. A banded variety of chalcedony, a cryptocrystalline form of quartz.
- oooh7interj. Elongated form of ooh.
- oops6interj. Used to acknowledge a small mistake or accident.
- ooze13n. Tanning liquor, an aqueous extract of vegetable matter (tanbark, sumac...
- opal6n. A mineral consisting, like quartz, of silica, but inferior to quartz in...
- open6adj. Able to have something pass through or along it.
- oppa8n. An affectionate term of address for an older brother or somewhat older...
- opus6n. A work of music or set of works with a specified rank in an ordering of...
- oral4adj. Relating to the mouth.
- orca6n. A sea mammal (Orcinus orca) related to dolphins and porpoises, commonly...
- orgy8n. A secret rite or ceremony, typically involving riotous and dissolute...
- osha7n. A perennial herb of species Ligusticum porteri, found in parts of the...
- ouch9interj. An expression of one's own physical pain.
- ours4pron. Excluding the person(s) being addressed (exclusive ours).
- oust4v. To expel; to remove.
- oval7n. A two-dimensional one.
- oven7n. A chamber used for baking or heating.
- over7adj. Finished; ended; concluded.
- owed8adj. That owes.
- oxen11adj. Of, relating to, or resembling an ox; oxlike.
5-letter words that start with O
- oasis5n. A spring of fresh water, surrounded by a fertile region of vegetation...
- obese7adj. Extremely overweight, especially: weighing more than 20% (for men) or...
- occur9v. To happen or take place.
- ocean7n. One of the large bodies of water separating the continents.
- oddly10adv. In a peculiar manner; strangely; unusually.
- odour6n. UK standard spelling of odor.
- offer11n. A proposal that has been made.
- often8adv. Frequently; many times on different occasions.
- oiled6adj. Covered in, or supplied with, oil.
- okada10n. A motorcycle taxi.
- olden6adj. From or relating to a previous era.
- older6adj. Elderly.
- olive8n. A tree of species Olea europaea cultivated since ancient times in the...
- ollie5n. An aerial maneuver in which one catches air by leaping off the ground...
- omega8n. The twenty-fourth letter of the Classical and the Modern Greek...
- onion5n. A monocotyledonous plant (Allium cepa), allied to garlic, used as...
- onset5n. The initial phase of a disease or condition, in which symptoms first...
- ooooh8interj. Elongated form of ooh.
- opera7n. A theatrical work, combining drama, music, song and sometimes dance...
- opium9n. A yellow-brown, addictive narcotic drug obtained from the dried juice...
- optic9adj. Of, or relating to the eye or to vision.
- orbit7n. An elliptical movement of an object about a celestial object or...
- order6n. Arrangement, disposition, or sequence.
- organ6n. The larger part of an organism, composed of tissues that perform...
- ortho8n. An isomer of a benzene derivative having two substituents adjacent on...
- oscar7n. A cichlid fish of species Astronotus ocellatus, native to South...
- other8adj. See other (determiner) below.
- otter5n. An aquatic or marine carnivorous mammal in the subfamily Lutrinae.
- ought9v. Indicating duty or obligation.
- ounce7n. An avoirdupois ounce, weighing ¹⁄₁₆ of an avoirdupois pound, or...
- outer5adj. Outside; external.
- outta5prep. Out of.
- ovary11n. A female reproductive organ, often paired, that produces ova in most...
- overt8adj. Open and not concealed or secret.
- owing9adj. Still to be paid; owed as a debt.
- owned9adj. Having an owner who is part of a specified group.
- owner8n. One who owns something.
- oxide13n. A binary chemical compound of oxygen with another chemical element.
- ozone14n. An allotrope of oxygen (symbol O₃) having three atoms in the molecule...
- ozzie23n. A hospital.
6-letter words that start with O
- object17n. A thing that has physical existence but is not alive.
- obtain8v. To get hold of; to gain possession of, to procure; to acquire, in any...
- occult10v. To cover or hide from view.
- occupy15v. To fill.
- oculus8n. The central boss of a volute.
- offend13v. To hurt the feelings of; to displease; to make angry; to insult.
- office14n. A ceremonial duty or service, particularly.
- offset12n. Anything that acts as counterbalance; a compensating equivalent.
- oldest7n. The oldest child in a family, or individual in a group.
- oliver9n. A small tilt hammer, worked by the foot.
- online6adj. Of a generator or power plant: connected to the grid.
- onward10adj. Moving forward.
- opaque17adj. Neither reflecting nor emitting light.
- opened9adj. Having undergone opening.
- opener8n. A person who opens something.
- openly11adv. In an open manner; visibly.
- opioid9n. Any of the natural substances, such as an endorphin, released in the...
- oppose10v. To attempt to stop the progression of; to resist or antagonize by...
- optics10n. The physics of light and vision: basic optical science.
- option8n. One of a set of choices that can be made.
- oracle8n. A shrine dedicated to some prophetic deity.
- orange7n. An evergreen tree of the genus Citrus such as Citrus sinensis which...
- orchid12n. A plant of the orchid family (Orchidaceae), bearing unusually-shaped...
- ordeal7n. A trial in which the accused was subjected to a dangerous test (such as...
- orient6n. The part of the horizon where the sun first appears in the morning; the...
- origin7n. The beginning of something.
- ornate6adj. Elaborately ornamented, often to excess.
- orphan11n. A person, especially a minor, both or (rarely) one of whose parents...
- others9n. Other people.
- outage7n. A temporary suspension of operation, especially of electrical power...
- outcry11n. A loud cry or uproar.
- outfit9n. A set of clothing (with accessories).
- outing7n. A pleasure trip or excursion.
- outlaw9n. A fugitive from the law.
- outlet6n. A vent or similar passage to allow the escape of something.
- output8n. Production; quantity produced, created, or completed.
- outset6n. An onset; the beginning or initial stage of something.
- overly12adv. To an excessive degree.
- oxygen17n. The chemical element (symbol O) with an atomic number of 8 and relative...
- oyster9n. Any of certain marine bivalve mollusks, especially those of the family...
7-letter words that start with O
- obesity12n. The state of being obese.
- obliged11adj. Under an obligation to do something.
- obscene11adj. Offensive to standards of decency or morality.
- obscure11adj. Dark, faint or indistinct.
- observe12v. To notice or view, especially carefully or with attention to detail.
- obvious12adj. Easily discovered, seen, or understood; self-explanatory.
- octopus11n. Any of several marine molluscs of the order Octopoda, having no...
- odyssey14n. An extended adventurous voyage, usually in search of home.
- offence15n. UK, Australia, New Zealand, and Canada standard spelling of offense.
- offense13n. A crime or sin.
- officer15n. One who has a position of authority in a hierarchical organization...
- offline13adj. Of a system, currently not connected (generally electrically) to a...
- omitted10adj. Left out; not included intentionally.
- onboard10adj. Carried or used on or in a vehicle or vessel.
- ongoing9adj. Continuing, permanent, lasting.
- onstage8adj. On the part of a stage that is visible to the audience.
- onwards11adv. Onward.
- opening10adj. Pertaining to the start or beginning of a series of events.
- operate9v. To perform a work or labour; to exert power or strength, physical or...
- opinion9n. A belief, judgment or perspective that a person has formed, either...
- opposed12adj. Acting in opposition; opposing.
- optical11adj. Of or relating to sight; visual.
- optimal11adj. The best, most favourable or desirable, especially under some...
- optimum13n. The best or most favorable condition, or the greatest amount or degree...
- orbital9adj. Of or relating to, or forming an orbit (such as the orbit of a moon...
- orchard13n. A garden or an area of land for the cultivation of fruit or nut trees.
- ordered9adj. In order, not messy, tidy.
- organic10adj. Pertaining to or derived from living organisms.
- ottoman9n. An upholstered sofa, without arms or a back, sometimes with a...
- outcome11n. That which is produced or occurs as a result of an event or process.
- outdoor8adj. Situated in, designed to be used in, or carried on in the open air.
- outline7n. A line marking the boundary of an object figure.
- outlook11n. A place from which something can be viewed.
- outrage8n. An excessively violent or vicious attack; an atrocity.
- outside8n. The part of something that faces out; the outer surface.
- outward11adj. Outer; located towards the outside.
- overall10adj. All-encompassing, all around.
- overdue11adj. Late; especially, past a deadline or too late to fulfill a need.
- overlap12v. To extend over and partly cover something.
- oversee10v. To survey, look at something in a wide angle.
8-letter words that start with O
- observed14adj. Exceptionally celebrated on a date other than the usual date.
- observer13n. One who makes observations, monitors or takes notice.
- obsessed11adj. Intensely preoccupied with or by a given topic or emotion; driven by a...
- obsolete10adj. No longer in use or no longer useful; now disused or neglected (often...
- obstacle12n. Something that impedes, stands in the way of, or holds up progress...
- occasion12n. A favorable opportunity; a convenient or timely chance.
- occupied15adj. Reserved; engaged.
- offender15n. One who gives or causes offense, or does something wrong.
- offering15n. The act by which something is offered.
- official16adj. Of or about an office or public trust.
- offshore17adj. Moving away from the shore.
- operated11adj. Operated by the means specified e.g. a battery-operated toy.
- operator10n. A person or organisation that operates a device, system, service, etc.
- opponent12n. One who opposes another; one who works or takes a position against...
- opposing13adj. That opposes or oppose; on the opposite side.
- opposite12adj. Located directly across from something else, or from each other.
- optimism14n. A tendency to expect the best, or at least, a favourable outcome.
- optional10adj. Not compulsory; left to personal choice; elective.
- ordering10n. Arrangement in a sequence.
- ordinary12n. A person having immediate jurisdiction in a given case of...
- organism11n. A discrete and complete living thing, such as animal, plant, fungus or...
- organize18v. To arrange in working order.
- oriented9adj. Having a specific orientation (positioning or direction).
- original9adj. Relating to the origin or beginning; preceding all others.
- orthodox19adj. Conforming to the accepted, established, or traditional doctrines of a...
- outbreak14n. An eruption; the sudden appearance of a rash, disease, etc.
- outdated10adj. Out of date, old-fashioned, antiquated.
- outdoors9adv. Not inside a house or under covered structure; unprotected; in the open...
- outgoing10adj. Extroverted: talkative, friendly, and social, especially with respect...
- outlined9adj. Containing an outline.
- outreach13n. The act of reaching out.
- outright12adv. Wholly; completely; entirely.
- outsider9n. Someone who is not part of a particular community, profession...
- overcome15v. To surmount (a physical or abstract obstacle); to prevail over, to get...
- overdose12n. An excessive and dangerous dose of a drug.
- overhaul14n. A major repair, renovation, or revision.
- overhead15adj. Located above, especially over the head.
- overseas11adj. Abroad, especially across the sea.
- overtime13n. Working time outside of one's regular hours.
- overview17n. A brief summary, as of a book or a presentation.
9-letter words that start with O
- obedience14n. The quality of being obedient.
- objection20n. The act of objecting.
- objective23adj. Of or relating to a material object, actual existence or reality.
- obligated13adj. Committed.
- oblivious14adj. Lacking awareness; unmindful; unaware, unconscious of.
- obnoxious18adj. Extremely offensive or unpleasant; very annoying, contemptible, or...
- observing15n. Observation.
- obsession11n. The quality of being obsessed; an unshakeable feeling that one topic or...
- obsessive14adj. Prone to cause obsession.
- obviously17adv. In an obvious or clearly apparent manner.
- occupancy20n. The act of occupying, the state of being occupied or the state of being...
- occurring14n. An instance of something occurring; an event or happening.
- offending17n. The act of committing an offence.
- offensive18adj. Causing offense; arousing a visceral reaction of disgust, anger...
- offspring18n. A person's daughter or son; a person's child.
- operating12adj. In operation; that operates.
- operation11n. The method by which a device performs its function.
- operative14adj. Effectual or important.
- oppressed14adj. Subject to oppression.
- optimized23adj. That has undergone optimization.
- orchestra14n. A large group of musicians who play together on various instruments...
- ordinance12n. A local law, passed by e.g. a city.
- organized20adj. Of things or settings, having been organized; in good order.
- organizer19n. A person who arranges the details of a public event.
- originate10v. To cause (someone or something) to be; to bring (someone or something)...
- orphanage15n. A residential institution for the care and protection of orphans.
- otherwise15adv. Differently, in another way.
- ourselves12pron. Us; the group including the speaker as the object of a verb or...
- outsiders10n. A pair of nippers for turning a key in a keyhole from the outside.
- outskirts13n. The area surrounding a city or town; suburb.
- outspoken15adj. Speaking, or spoken, freely, openly, or boldly; vocal; frank.
- overboard15adj. Outside of a boat; in the water.
- overnight16adv. During or throughout the night, especially during the evening or night...
- overrated13adj. Given an undue amount of credit for quality or merit in a field; not...
- oversight16n. An omission; something that is left out, missed, or forgotten.
- oversized22adj. Very large; especially of something larger than normal for its type.
- overthrow18v. To bring about the downfall of (a government, etc.), especially by...
- overwatch20v. To watch over.
- ownership17n. The state of having complete legal control of something; possession...
- oxidation17n. The combination of a substance with oxygen.
10-letter words that start with O
- obligation13n. The act of binding oneself by a social, legal, or moral tie to someone.
- obligatory16adj. Imposing obligation, legally, morally, or otherwise; binding; mandatory.
- observable17adj. Able to be observed.
- observance17n. The practice of complying with a law, custom, command or rule.
- obstetrics14n. The care of women during and after pregnancy.
- obtainable14adj. Able to be obtained.
- occasional14adj. Occurring or appearing irregularly from time to time, but not often...
- occupation16n. An activity or task with which one occupies oneself; usually...
- occurrence16n. An actual instance when a situation occurs; an event or happening.
- officially21adv. In an official manner; according to official rules or regulations.
- oftentimes15adv. Frequently; often.
- operations12n. Any practically minded combination of business administration...
- opposition14n. The action of opposing or of being in conflict.
- oppression14n. The exercise of authority or power in a burdensome, cruel, or unjust...
- oppressive17adj. Burdensome or difficult to bear.
- optimistic16adj. Expecting the best in all possible ways.
- optimizing24adj. Carrying out optimization.
- orchestral15adj. Relating to an orchestra or to music played by an orchestra.
- ordinarily14adv. Usually or as a general rule; commonly.
- ordination11n. The act of ordaining or the state of being ordained.
- organising12n. The act or process by which something is organised.
- organizing21n. The act or process by which something is organized.
- originally14adv. As it was in the beginning; at first.
- ornamental12adj. Serving as an ornament; having no purpose other than to make more...
- orthopedic18adj. Of or relating to orthopedics.
- ostensibly15adv. Seemingly, apparently, on the surface; supposedly, according to...
- outfielder14n. A player that plays in the outfield, which is the outer portion of the...
- outlandish14adj. Appearing to be foreign; strange, unfamiliar.
- outpatient12n. A patient who receives treatment at a hospital or clinic but is not...
- outperform17v. To perform better than something or someone.
- outrageous11adj. Violating morality or decency; provoking indignation or affront.
- outsourced13adj. Obtained by outsourcing.
- overcoming18n. The act by which something is overcome, or surmounted.
- overloaded15adj. Loaded too heavily.
- overlooked18adj. Missed, unnoticed.
- overpriced18adj. Priced higher than its real worth.
- overriding15n. The act or process by which something is overridden.
- overtaking18n. The act by which one thing overtakes another.
- overweight20adj. Having a higher weight, especially body fat, than what is generally...
- overworked21adj. Subjected to too much work.
11-letter words that start with O
- obfuscation18n. The act or process of obfuscating, or obscuring the perception of...
- objectively28adv. In an impartial, objective manner.
- objectivity28n. The state of being objective, just, unbiased, and not influenced by...
- obliterated14adj. Destroyed; (loosely) broken beyond repair.
- observation16n. The act of observing, and the fact of being observed (see observance).
- observatory19n. A place where stars, planets and other celestial bodies are observed...
- obsessively19adv. In an obsessive manner.
- obstruction15n. The act of obstructing, or state of being obstructed.
- obstructive18adj. Causing obstructions.
- offensively23adv. In an offensive manner.
- omnipresent15adj. Being everywhere simultaneously.
- ontological14adj. Of or relating to ontology.
- operational13adj. Of or relating to operations, especially military operations.
- opinionated14adj. Having very strong opinions.
- opportunist15n. Someone who takes advantage of any opportunity to advance their own...
- opportunity18n. A chance for advancement, progress or profit.
- orchestrate16v. To arrange or score music for performance by an orchestra.
- organically17adv. In an organic manner.
- orientation11n. The determination of the relative position of something or someone.
- originality15n. The quality of being original or novel.
- origination12n. The process of bringing something into existence.
- orthography23n. A method of representing a language or the sounds of language by...
- oscillating14adj. Moving in a repeated back-and-forth motion; coming and going.
- oscillation13n. The act of oscillating or the state of being oscillated.
- osteopathic18adj. Of or pertaining to osteopathy or osteopathic medicine.
- outsourcing14n. The transfer of a business function to an external service provider.
- outstanding13adj. Prominent or noticeable; sovereign.
- overarching20adj. Arching over; that forms an arch overhead.
- overbearing17adj. Overly bossy, domineering, arrogant, forceful, intense, or annoying.
- overcrowded21adj. Containing too many occupants for an area of its size.
- overflowing21n. Overflow.
- overhanging19n. Synonym of overhang.
- overhauling18n. The act by which something is overhauled.
- overheating18n. A situation where something is overheated.
- overlapping19adj. That overlaps something else.
- overloading16n. A type of polymorphism, where different functions, operators or...
- overpowered20adj. Subdued by superior force.
- overturning15n. The act by which something is overturned.
- overwhelmed23adj. Emotionally overpowered.
- overzealous23adj. Too zealous; too enthusiastic or fervent.
12-letter words that start with O
- objectifying30n. Objectification.
- obliterating15adj. Causing obliteration; devastating.
- obliteration14n. The total destruction of something.
- obsolescence18n. The state of being obsolete—no longer in use; gone into disuse; disused...
- obstetrician16n. A physician who specializes in childbirth.
- occasionally19adv. On occasion: at relatively infrequent intervals, from time to time...
- occupational18adj. Of, belonging, or relating to an occupation (in any sense).
- oceanography23n. The exploration and scientific study of the oceans and ocean floor.
- octogenarian15n. Synonym of eightysomething: a person between 80 and 89 years old.
- onomatopoeia16n. The property of a word that sounds like what it represents.
- oppositional16adj. Of, pertaining to, or exhibiting opposition.
- optimization25n. The design and operation of a system or process to make it as good as...
- organisation13n. Non-Oxford British English and Australian standard spelling of...
- organization22n. The quality of being organized.
- orienteering13n. The act of racing across unfamiliar place using a map and compass.
- orthodontics18n. A specialty of dentistry concerned with correcting misalignment of...
- orthodontist16n. An orthodontic dentist.
- orthographic23adj. Of a projection used in maps, architecture etc., in which the rays are...
- oscilloscope18n. An electronic measuring instrument that creates a visible...
- ostentatious12adj. Of ostentation.
- osteoporosis14n. A disease, occurring especially in women following menopause, in which...
- osteosarcoma16n. A type of cancer of the bone.
- otherworldly22adj. Of, concerned with, or preoccupied with a world different from the...
- outrageously16adv. In an outrageous manner; to an outrageous degree.
- outstretched18adj. Extended or stretched out.
- overburdened19adj. Excessively burdened.
- overcharging22n. The act or process of charging excessively.
- overclocking24n. An instance or incident of processor (CPU), or any electronic logic...
- overcrowding22n. The situation where a space holds more occupants than it can...
- overdramatic20adj. Dramatic to excess.
- overestimate17v. To judge or calculate too highly.
- overexposure24n. Excessive exposure.
- overextended24adj. Extended or expanded beyond a safe limit.
- overpowering21adj. That overpowers; so strong as to be overwhelming.
- overreaching21adj. That overreaches (all senses).
- overreaction17n. A reaction that is excessive.
- overshadowed23adj. Superseded by, covered up by, overtaken or eclipsed.
- overspending19n. The spending of too much money.
- overthinking23n. The act of thinking too much about something.
- overwhelming24adj. Overpowering, staggering, or irresistibly strong.
13-letter words that start with O
- objectionable26adj. Arousing disapproval; worthy of objection; offensive.
- obliviousness18n. The characteristic of being oblivious.
- observability23n. The state of being observable.
- observational18adj. Relating to observation, especially scientific observation.
- obsessiveness18n. The characteristic of being obsessive.
- oceanographer21n. A person who studies oceanography, the science of oceans.
- oceanographic23adj. Relating to oceanography, the science of oceans.
- offensiveness22n. The quality of being offensive.
- ontologically19adv. In an ontological manner.
- operationally18adv. In an operational manner; in accordance with an operation.
- ophthalmology27n. The anatomy, functions, pathology, and treatment of the eye.
- opportunistic19adj. Taking advantage of situations that arise.
- orbitofrontal18adj. Located in the frontal lobes above the orbits of the eyes.
- orchestration18n. The arrangement of music for performance by an orchestra.
- organogenesis15n. The formation and development of the organs of an organism from...
- ornamentation15n. Decoration, adornment or embellishment.
- ornithologist17n. A person who studies or practices ornithology.
- oropharyngeal22adj. Of or pertaining to both the mouth and the pharynx.
- orthogonality20n. The property of being orthogonal.
- osteomyelitis18n. An infection of the bone.
- osteonecrosis15n. Avascular necrosis.
- outmaneuvered19adj. Overcome by the maneuvering of others.
- outspokenness19n. The quality of being outspoken.
- outstandingly18adv. In an outstanding manner.
- overabundance21n. An excess of what is needed or is appropriate.
- overconfident22adj. Too confident.
- overdeveloped23adj. Overgrown.
- overdiagnosis18n. The act or process of diagnosing something too frequently, or based on...
- overemphasize32v. To place too much emphasis on; to overstate the importance of.
- overexpressed26adj. Produced by overexpression.
- overpopulated21adj. Having or consisting of a higher population than can be sustained.
- overqualified29adj. Having too many qualifications to be deemed appropriate for a (usually...
- oversaturated17adj. Synonym of supersaturated.
- oversensitive19adj. Having excessive sensitivity; reacting to stimuli too readily...
- overshadowing24n. A dominating shadow or malign influence.
- overstatement18n. An exaggeration; a statement in excess of what is reasonable.
- overstretched22adj. Subject to demands that are more than can be reasonably handled.
- overvaluation19n. An instance of overvaluing.
- overwintering20n. The action of overwintering.
- oystercatcher23n. Any of several black or pied coastal wading birds in the genus...
14-letter words that start with O
- obsequiousness25n. The quality of being obsequious; servile compliance.
- obstructionism20n. A deliberate policy of obstructing something, especially a political...
- obstructionist18n. Someone who systematically obstructs the actions of others.
- occupationally23adv. As part of an occupation.
- onchocerciasis23n. A disease caused by a worm of the genus Onchocerca, especially as...
- operationalize25v. To make operational.
- ophthalmologic27adj. Ophthalmological.
- ophthalmoscope28n. An instrument for examining the interior of the eye (that is, for...
- optimistically23adv. In an optimistic manner.
- optoelectronic20adj. Of or pertaining to optoelectronics.
- organizational24adj. Of, relating to, or produced by an organization.
- organochlorine20n. Any of very many chlorine substituted organic compounds, many of which...
- organometallic19adj. Of, or relating to organic compounds having a metal atom directly...
- ornithological20adj. Of or pertaining to ornithology.
- orthographical25adj. Of, or relating to orthography or spelling.
- orthophosphate27n. Any salt or ester of orthophosphoric acid; an ordinary phosphate.
- ostentatiously17adv. In an ostentatious manner; extravagantly or flamboyantly.
- osteoarthritis17n. A form of arthritis, affecting mainly older people, caused by chronic...
- otolaryngology22n. The study of diseases of the ear, nose and throat.
- outperformance23n. The act or state of outperforming.
- outrageousness15n. The quality of being outrageous.
- overcompensate23v. To do an excessive amount in one area in an effort to overcome a...
- overcomplicate25v. To make something excessively complicated.
- overconfidence25n. An excessive or unwarranted degree of confidence.
- overcorrection21n. The correction of something to an excessive degree, usually resulting...
- overdetermined21adj. Having more constraints or causes than necessary to determine a...
- overestimation19n. The act of overestimating.
- overexpression26n. The abnormal or artificial expression of a gene in increased quantity.
- overindulgence21n. An act of overindulging; indulgence in too much; pleasure or...
- overpopulation21n. An excessive number of occupants (people, animals, plants, etc.) in a...
- overpoweringly26adv. In an overpowering manner.
- overproduction22n. The production of more of a commodity than can be used or sold.
- overprotective24adj. Excessively protective, wanting to give too much protection (especially...
- overregulation18n. Excessive regulation: too many rules, especially misguidedly conceived...
- oversaturation17n. Supersaturation.
- oversimplified25adj. Having been simplified to the point where important information is not...
- overstimulated20adj. Excessively stimulated.
- oversubscribed24adj. Having insufficient capacity to meet the demand of those who are...
- overwhelmingly29adv. In an overwhelming manner; very greatly or intensely.
- oxidoreductase25n. Any enzyme that catalyzes an oxidation-reduction (redox) reaction.
15-letter words that start with O
- objectification31n. The act or process of objectifying something intangible.
- observationally23adv. In an observational way.
- oceanographical25adj. Of or pertaining to oceanography, the science of oceans.
- oligodendrocyte23n. Any of the cells of the oligodendroglia in the nervous system.
- oligohydramnios25n. A deficit of amniotic fluid in the amniotic sac, causing distinctive...
- oligomerization27n. The formation of an oligomer from a monomer.
- oligonucleotide19n. A short sequence of nucleotides (RNA or DNA), typically with twenty or...
- oligosaccharide24n. A polysaccharide of low molecular weight, being a polymer of between...
- omnidirectional20adj. In every direction, especially of a radio system capable of...
- ontogenetically21adv. Synonym of ontogenically.
- ophthalmologist26n. A medical doctor specializing in the eye: deficiencies of vision...
- ophthalmoplegia28n. A complete paralysis of the extraocular muscles which are responsible...
- optoelectronics21n. The branch of physics that deals with the interaction of light with...
- organophosphate26n. Any ester of phosphoric acid or its derivatives, especially one used as...
- ornithorhynchus29n. A platypus (genus Ornithorhynchus).
- orthophosphoric30adj. Describing the ordinary form of phosphoric acid and its derivatives.
- osteochondritis21n. Inflammation of a bone and its cartilage.
- overachievement28n. A greater than anticipated achievement.
- overcomplicated27adj. Excessively complicated.
- overconsumption24n. Excessive consumption.
- overdevelopment26n. Excessive development; the state or quality of being overdeveloped.
- overrepresented21adj. Represented to an excessive degree, or in excessive numbers.
- oversensitivity24n. The state or quality of being excessively sensitive.
- overstimulation20n. Excessive stimulation.
- overutilization27n. Excessive utilization; overuse.
- overzealousness27n. The quality of being too zealous.
- oxytetracycline32n. A yellow crystalline broad-spectrum tetracycline antibiotic C₂₂H₂₄N₂O₉...
9,944 rare words that start with O
- oafdom
- oafishly
- oafishness
- oaflike
- oakbark
- oakenshaw
- oakiness
- oakless
- oaklet
- oaklike
- oakling
- oakness
- oaktag
- oakware
- oakworm
- oangium
- oarage
- oarhole
- oarless
- oarlessness
- oarlike
- oarlock
- oarsmanship
- oarsperson
- oarswoman
- oarweed
- oary
- oasal
- oasean
- oasification
- oasisless
- oasislike
- oasitic
- oatbread
- oateater
- oatenmeal
- oater
- oatflake
- oatgrass
- oathable
- oathbound
- oathbreach
- oathbreaking
- oathful
- oathless
- oathlet
- oathlike
- oathmaker
- oathsex
- oathsworn
- oathtaker
- oathtaking
- oathworthy
- oatie
- oatiness
- oatlage
- oatless
- oatlike
- oatmealish
- oatmealy
- oatstraw
- oatsy
- obacunone
- obai
- obaichthyid
- obake
- obambulate
- obambulation
- obang
- obaship
- obatoclax
- obazoan
- obbattu
- obcell
- obclavate
- obcompressed
- obconic
- obconically
- obcordate
- obcordately
- obcordiform
- obdeltate
- obdeltoid
- obdiplostemony
- obdormition
- obduce
- obduct
- obdurance
- obdurant
- obdurantly
- obdurateness
- obduration
- obdurator
- obdure
- obduredness
- obeahman
- obeast
- obebioside
- obeche
- obedible
- obedienciary
- obediency
- obediential
- obedientially
- obedientialness
- obedientiary
- obedientness
- obeisant
- obeisantly
- obeldesivir
- obelia
- obeliac
- obelic
- obelin
- obelion
- obeliscal
- obeliscar
- obeliscolychny
- obeliskine
- obelisklike
- obeliskoid
- obelism
- obelize
- obelized
- oberek
- oberhefe
- oberration
- obeseism
- obesely
- obeseness
- obeside
- obesification
- obesify
- obesogen
- obesogenesis
- obesogenicity
- obesophobia
- obestatin
- obetrioside
- obeyable
- obeyance
- obeyer
- obeyeth
- obeyingly
- obfirm
- obfirmation
- obfuscatable
- obfuscational
- obfuscator
- obfuscatorily
- obfuscity
- obfuscous
- obfusticate
- obfustication
- obicetrapib
- obidoxime
- obiism
- obijime
- obiltoxaximab
- obinutuzumab
- obital
- obitual
- obituarial
- obituarian
- obituarily
- obituarist
- obituarize
- objectable
- objectal
- objectality
- objectant
- objectee
- objectful
- objecthood
- objectifiable
- objectifier
- objectingly
- objectional
- objectioner
- objectionism
- objectionist
- objectism
- objectist
- objectival
- objectivate
- objectivation
- objectivistic
- objectivization
- objectivize
- objectivizer
- objectization
- objectize
- objectless
- objectlessly
- objectlessness
- objectlike
- objectness
- objectophile
- objectophilia
- objectress
- objectrix
- objectual
- objectually
- objectum
- objicient
- objuration
- objuratory
- objure
- objurgate
- objurgation
- objurgative
- objurgatively
- objurgator
- objurgatorily
- objurgatory
- oblanceolately
- oblastal
- oblately
- oblational
- oblationary
- oblationer
- oblative
- oblatory
- oblatration
- oblatum
- oblea
- oblectate
- oblectation
- obley
- obligability
- obligable
- obligala
- obligancy
- obligant
- obligatedly
- obligatee
- obligational
- obligative
- obligativeness
- obligator
- obligatoriness
- obligatorize
- obligatum
- obligedly
- obligedness
- obligement
- obliger
- obligingness
- oblimax
- oblimersen
- oblimin
- obliquangular
- obliquation
- obliqueness
- obliquid
- obliquitous
- obliquolateral
- obliterable
- obliteratingly
- obliterationism
- obliterative
- obliteratively
- obliterature
- oblivescence
- oblivescent
- oblivial
- obliviality
- obliviation
- oblivionate
- oblivionize
- obliviscence
- oblocutor
- obloid
- oblongatal
- oblongate
- oblongichytrid
- oblongish
- oblongitude
- oblongitudinal
- oblongly
- oblongness
- oblongular
- oblongum
- obloquial
- obloquious
- obluctation
- oblyrate
- obmurmuration
- obmutescence
- obmutescent
- obnebulate
- obnosis
- obnoxiety
- obnoxiosity
- obnoxity
- obnubilate
- obnubilated
- obnubilation
- obnubilous
- oboelike
The first 300 are shown.
Questions about these words
- How many words that start with O are there?
- Word.ws lists 1,958 words that start with O, plus 9,944 rare ones.
- What are common words that start with O?
- of, on, or, one, out, other, our and only.
- Which of the words that start with O has the highest letter score?
- oxcarbazepine scores 35 points with the standard letter tile values.
Related word lists
Source and license
Word lists and meanings adapted from the Wiktionary entry of each word. Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws left out names, abbreviations, misspellings and offensive words, and ordered the most common words by how often they appear in English (wordfreq). Meanings from Wiktionary; this is not an official Scrabble, Words With Friends or Wordle word list. Wiktionary data of 2026-09-02.
Cite this page: “Words That Start with O: 1,958 Words by Length.” Word.ws, https://word.ws/words/starting-with-o. Based on Wiktionary, CC BY-SA 4.0.