Words that start with O

Lists of words starting with O including those most commonly written / spoken, definitions, part of speech, and a very long list arranged by word length. Also includes countries that start with O, household items that begin with O, and more. Skip to the section you’re interested in by using the Table Of Contents, or scroll down to see more o words.

Common / frequently used:

Top 10 most common written words ordered by frequency:
of on or one other out only our over own

Common written words in alphabetic order:
of on one only or other our out over own

Top 20 most common spoken O words by frequency:
of on one or out oh okay over other our off only old own open once ones outside order oil

Glossary with part of speech and definition for the top 200 or so most frequently used O words:

oak noun the hard durable wood of any oak; used especially for furniture and flooring
oar noun an implement used to propel or steer a boat
oasis noun a fertile tract in a desert (where the water table approaches the surface)
oat noun annual grass of Europe and North Africa; grains used as food and fodder (referred to primarily in the plural: `oats’)
oatmeal noun porridge made of rolled oats
obedience noun the act of obeying; dutiful or submissive behavior with respect to another person
obedient adjective dutifully complying with the commands or instructions of those in authority; ; ; ; – Edmund Burke
obey verb be obedient to
obituary noun a notice of someone’s death; usually includes a short biography
object noun a tangible and visible entity; an entity that can cast a shadow
objectionable adjective causing disapproval or protest
objectivity noun judgment based on observable phenomena and uninfluenced by emotions or personal prejudices
obligatory adjective morally or legally constraining or binding
oblique noun any grammatical case other than the nominative
oblivion noun the state of being disregarded or forgotten
oblivious adjective (followed by `to’ or `of’) lacking conscious awareness of
oblong noun a plane figure that deviates from a square or circle due to elongation
obscene adjective designed to incite to indecency or lust; -Margaret Mead
obscure verb make less visible or unclear
observant adjective paying close attention especially to details
observation noun the act of making and recording a measurement
observatory noun a building designed and equipped to observe astronomical phenomena
obsessive noun a person who has obsessions
obstacle noun something immaterial that stands in the way and must be circumvented or surmounted
obstinate verb persist stubbornly
obstruct verb hinder or prevent the progress or accomplishment of
obstruction noun any structure that makes progress difficult
obtain verb come into possession of
obtuse adjective of an angle; between 90 and 180 degrees
obviate verb do away with
obvious adjective easily perceived by the senses or grasped by the mind
occasional adjective occurring from time to time
occasionally adverb now and then or here and there
occipital adjective of or relating to the occiput
occlusion noun closure or blockage (as of a blood vessel)
occupancy noun an act of being a tenant or occupant
occupation noun the principal activity in your life that you do to earn money
occupational adjective of or relating to the activity or business for which you are trained
ocean noun a large body of water constituting a principal part of the hydrosphere
octave noun a feast day and the seven days following it
odd adjective not divisible by two
odds noun the likelihood of a thing occurring rather than not occurring
ode noun a lyric poem with complex stanza forms
oeuvre noun the total output of a writer or artist (or a substantial part of it)
offer noun the verbal act of offering
office noun place of business where professional or clerical duties are performed
official noun a worker who holds or is invested with an office
officially adverb in an official role
offshore adjective (of winds) coming from the land
offspring noun the immediate descendants of a person
oil noun a slippery or viscous liquid or liquefiable substance not miscible with water
ointment noun semisolid preparation (usually containing a medicine) applied externally as a remedy or for soothing an irritation
old noun past times (especially in the phrase `in days of old’)
olden adjective long past
olfactory adjective of or relating to olfaction
oligarchy noun a political system governed by a few people
olive noun small ovoid fruit of the European olive tree; important food and source of oil
omega noun the ending of a series or sequence; –Revelation
omen noun a sign of something about to happen
omission noun a mistake resulting from neglect
omnibus noun an anthology of articles on a related subject or an anthology of the works of a single author
omnipotence noun the state of being omnipotent; having unlimited power
omnipresent adjective being present everywhere at once
on adjective in operation or operational
once adverb on one occasion
oncology noun the branch of medicine concerned with the study and treatment of tumors
one noun the smallest whole number or a numeral representing this number
oneness noun the quality of being united into one
ongoing adjective currently happening
onion noun the bulb of an onion plant
onset noun the beginning or early stages
onslaught noun a sudden and severe onset of trouble
onstage adjective situated or taking place on the area of a stage visible to the audience
ontology noun (computer science) a rigorous and exhaustive organization of some knowledge domain that is usually hierarchical and contains all the relevant entities and their relations
opacity noun the phenomenon of not permitting the passage of electromagnetic radiation
opaque adjective not transmitting or reflecting light or radiant energy; impenetrable to sight
open noun a clear or unobstructed space or expanse of land or water
opener noun the first event in a series
opening noun an open or empty space in or between things
opera noun a drama set to music; consists of singing with orchestral accompaniment and an orchestral overture and interludes
operate verb direct or control; projects, businesses, etc.
operatic adjective of or relating to or characteristic of opera
operation noun the state of being in effect or being operative
operational adjective pertaining to a process or series of actions for achieving a result
operator noun (mathematics) a symbol or function representing a mathematical operation
opinion noun a personal belief or judgment that is not founded on proof or certainty
opium noun an addictive narcotic extracted from seed capsules of the opium poppy
opportune adjective suitable or at a time that is suitable or advantageous especially for a particular purpose
opportunity noun a possibility due to a favorable combination of circumstances
oppose verb be against; express opposition to
oppress verb come down on or keep down by unjust use of one’s authority
oppression noun the act of subjugating by cruelty
oppressive adjective weighing heavily on the senses or spirit
optical adjective of or relating to or involving light or optics
optics noun the branch of physics that studies the physical properties of light
optimism noun the optimistic feeling that all is going to turn out well
optimistic adjective expecting the best in this best of all possible worlds
optimize verb make optimal; get the most out of; use best
optimum noun most favorable conditions or greatest degree or amount possible under given circumstances
option noun the right to buy or sell property at an agreed price; the right is purchased and if it is not exercised by a stated date the money is forfeited
optional adjective possible but not necessary; left to personal choice
oral noun an examination conducted by spoken communication
orange noun round yellow to orange fruit of any of several citrus trees
oration noun an instance of oratory
orator noun a person who delivers a speech or oration
oratory noun addressing an audience formally (usually a long and rhetorical address and often pompous)
orbit noun the (usually elliptical) path described by one celestial body in its revolution about another
orbital adjective of or relating to an orbit
orchestra noun a musical organization consisting of a group of instrumentalists including string players
orchestral adjective relating to or composed for an orchestra
ordeal noun a severe or trying experience
order noun (often plural) a command given by a superior (e.g., a military or law enforcement officer) that must be obeyed
orderly noun a soldier who serves as an attendant to a superior officer
ordinary noun a judge of a probate court
ordinate noun the value of a coordinate on the vertical axis
ordination noun the status of being ordained to a sacred office
ore noun a mineral that contains metal that is valuable enough to be mined
organ noun a fully differentiated structural and functional unit in an animal that is specialized for some particular function
organic noun a fertilizer that is derived from animal or vegetable matter
organism noun a living thing that has (or can develop) the ability to act or function independently
organist noun a person who plays an organ
organization noun a group of people who work together
organizational adjective of or relating to an organization
organizer noun a person who brings order and organization to an enterprise
orgasm noun the moment of most intense pleasure in sexual intercourse
orientation noun the act of orienting
orifice noun an aperture or hole that opens into a bodily cavity
originality noun the ability to think and act independently
originally adverb in an original manner
originate verb come into existence; take on form or shape
ornamental noun any plant grown for its beauty or ornamental value
ornamentation noun the state of being ornamented
orphan noun a child who has lost both parents
orphanage noun the condition of being a child without living parents
orthodoxy noun the quality of being orthodox (especially in religion)
os noun a mouth or mouthlike opening
oscillation noun the process of oscillating between states
oscillator noun generator that produces sonic oscillations or alternating current
osteoporosis noun abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium; most common in postmenopausal women
osteotomy noun surgical sectioning of bone
ostrich noun a person who refuses to face reality or recognize the truth (a reference to the popular notion that the ostrich hides from danger by burying its head in the sand)
other adjective not the same one or ones already mentioned or implied; – the White Queen
otherness noun the quality of being not alike; being distinct or different from that otherwise experienced or known
otherwise adjective other than as supposed or expected
otter noun the fur of an otter
ounce noun a unit of apothecary weight equal to 480 grains or one twelfth of a pound
out noun (baseball) a failure by a batter or runner to reach a base safely in baseball
outbreak noun a sudden violent spontaneous occurrence (usually of some undesirable condition)
outcast noun a person who is rejected (from society or home)
outdated adjective old; no longer valid or fashionable
outdoor adjective located, suited for, or taking place in the open air
outdoors noun where the air is unconfined
outer adjective being on the outside or further from a center
outfit noun any cohesive unit such as a military company
outgrowth noun a natural consequence of development
outline noun the line that appears to bound an object
outlying adjective relatively far from a center or middle
outpatient noun a patient who does not reside in the hospital where he is being treated
outreach noun the act of reaching out
outright adjective without reservation or exception
outside noun the region that is outside of something
outskirts noun outlying areas (as of a city or town)
outspoken adjective given to expressing yourself freely or insistently
outstanding adjective distinguished from others in excellence
outstretched adjective fully extended especially in length
outward adjective relating to physical reality rather than with thoughts or the mind
outwardly adverb with respect to the outside
outweigh verb be heavier than
ovarian adjective of or involving the ovaries
ovary noun the organ that bears the ovules of a flower
oven noun kitchen appliance used for baking or roasting
over noun (cricket) the division of play during which six balls are bowled at the batsman by one player from the other team from the same end of the pitch
overall noun (usually plural) work clothing consisting of denim trousers (usually with a bib and shoulder straps)
overboard adverb to extremes
overdose verb dose too heavily
overhaul noun periodic maintenance on a car or machine
overland adjective traveling or passing over land
overlap noun a representation of common ground between theories or phenomena
overload noun an electrical load that exceeds the available electrical power
overlook noun a high place affording a good view
override noun a manually operated device to correct the operation of an automatic device
oversee verb watch and direct
overseer noun a person who directs and manages an organization
oversight noun an unintentional omission resulting from failure to notice something
overt adjective open and observable; not secret or hidden
overtake verb catch up with and possibly overtake
overthrow noun the termination of a ruler or institution (especially by force)
overtime noun work done in addition to regular working hours
overtly adverb in an overt manner
overture noun orchestral music played at the beginning of an opera or oratorio
overview noun a general summary of a subject
overwhelm verb overcome, as with emotions or perceptual stimuli
owe verb be obliged to pay or repay
owl noun nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes
own verb have ownership or possession of
owner noun (law) someone who owns (is legal possessor of) a business
ownership noun the relation of an owner to the thing possessed; possession with the right to transfer possession to others
ox noun an adult castrated bull of the genus Bos; especially Bos taurus
oxidase noun any of the enzymes that catalyze biological oxidation
oxidation noun the process of oxidizing; the addition of oxygen to a compound with a loss of electrons; always occurs accompanied by reduction
oxide noun any compound of oxygen with another element or a radical
oxygen noun a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth’s crust
oyster noun marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters
ozone noun a colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)

Questions and Answers:

Q: What is the longest O word and how many letters does it have in it?
A: The word overindividualistically is 23 letters long.

Q: What is the shortest word that starts with O?
A: “On” is just two letters long and begins with O.

Q: What countries start with the letter O?
A: Oman.

Q: What are some household items / things / objects that start with O?
A: oven

O words by number of letters:

More complete list, by word length:

2 letter words beginning with o:

od of oh oi ok on or os ow ox

3 letter words beginning with o:

oaf oak oam oar oat obe obi och odd ode oes off oft ohm oho oii oil oka oke oki old one oof ope opt ora orb ore org oud oui our out ova owe owl own

4 letter words beginning with o:

oars oary oast oath obey obit obli oboe odds odin odor odyl ofay ogee ogle ogre ohia oily oink okay okra oleo olid olio olla omen omer omit omni once only onto onus onyx oons oops oosy ooze oozy opah opal open opus oral orbs orch ordn orgy orle orlo orts

oryx otic otto ouch ouds ould ours oust outr ouzo oval oven over ovum owls owly oxen oxer oyer oyez

5 letter words beginning with o:

oaken oakum oared oasis oaten obang obeah obese objet oboli occur ocean ocher ochre ocrea octad octal octan octet ocyte odeum odium oelet offal offer often ofter ogham ogive oiler okapi okehs olden older oldie oleic olein olena oleum olive ology omasa ombre omega omnes onces onion onker onkus onset onymy

oomph ootid opera opine opium opsin opted optic orang orant orate orbit order oread orgal organ oriel orlet orlop ornis orris oside osier osmic osmol other ottar otter ought ounce ouphe ousel ousts outdo outer outgo ouzel ovary ovate overt ovine ovoid ovoli ovolo ovule owing owlet owner owrie owsen oxbow oxide oxime ozena ozone

6 letter words beginning with o:

oatbin oathed obduce obdure obeish obelia obispo object oblast oblate oblige oblong oboles obolus obsess obtain obtect obtest obtund obtuse obvert occult occupy ocelot ochone ochrea ochres ochrey octane octant octave octavo octine octode octroi ocular oculus oddity odious odored odours oedema oenone oeuvre offcut offend office offing offish offset ogdoad

ogived ogrish ohioan ohmage oidium oilcan oilcup oitava okayed oldest oleate oleums ollavs olluck omahas omasum omelet omenta onager onrush onward onyxes oocyte oodles oohing oolite oology oompah oomphs opacus opaque opener operon ophite opiate opines oppose oppugn optics optime option oracle orange orangy orator orbite orbity orcein orchel orchid ordain

ordeal orders ordure orgamy orgasm orgeat orgues orient origan origin orihon oriole orison orlons ormolu ornate ornery orphan orpine orrery oscine osiris osmite osmium osmose osprey ossein ossify osteal ostium ostler ostomy otiose otitis otosis ottava otters oughly ouijas oursel ouster outage outawe outbid outbuy outcry outdid outfit outfox outing outlaw outlay outlet outman output outred outrun

outset outwit ovator overdo overly ovibos ovular owling owlish owners oxacid oxalis oxalyl oxcart oxford oxhorn oxonic oxtail oxters oxwort oxygen oxygon oyster ozalid

7 letter words beginning with o:

oakland oarfish oarless oarlock oarsman oatcake oatmeal obadiah obeahed obelisk obelize obiisms obligee obligor oblique obloquy obovate obovoid obscene obscure observe obtends obtrude obverse obviate obvious ocarina occiput occlude occults oceanic ocelots ocreate octagon octapla octopod octopus octuple oculist ocypode oddball oddment oddness odontic odorous odylism oenomel oersted oestrin offbeat offence

offense offeror offhand officer offices offside oficina oghamic ohmages oilbird oilcake oilcase oiliest oillike oilskin oinomel okimono okonite oldster oldwife olearia oligist olingos olivine oloroso olycook omander omental omentum ominous omnibus onagers onanism oncomes oneiric oneness onerate onerose onerous oneself onetime ongoing onshore onstage onwards oocysts ooplasm oosperm oospore opacity opaline opening operand operant operate operose

ophidia opiated opinion opossum oppidan opposed oppress opsonin optical optimal optimum opulent opuntia oquassa orarion oration oratory oratrix orbital orchard orchats orchels orcinol orderly ordinal ordinar orectic oregano orfrays organdy organic organon organza oriency orifice origami origane origins orogeny orotund orphrey ortolan oscular osculum osiered osmious osmiums osmosis osmunda osseous ossicle ossuary ostemia osteoid osteoma ostiary ostiole ostmark ostosis

ostraka ostrich otacust otalgia othmany otiatry otocyst otolith otology ottetto ottoman ouabain oubliet ouching ouguiya ourangs ourself outages outbond outbray outbulk outcast outcome outcrop outdare outdate outdoes outdoor outdrop outearn outface outfall outfelt outflow outfoot outform outgate outgrow outguns outhaul outhunt outland outlast outleap outlier outlimn outline outlive outlook outmost outpeep outpity outplay outport outpost outpour outrage

outrank outrate outride outroar outroll outrove outrows outrung outrush outsail outsell outsert outsets outshow outside outsize outskip outsoar outsole outspan outspit outstay outstep outtalk outtear outtold outtops outtore outtorn outturn outvier outvote outward outwars outwash outwave outwear outwore outwork outworn ovarian ovaries ovating ovation overact overage overall overarm overawe overbid overbig overden overdry overdue overdye

overeat overfar overfly overjoy overlap overlay overleg overlie overman overpay overply overrun oversay oversee overset oversew oversot overtax overtly overtop overuse oviduct oviform owlhead owriest oxalate oxazine oxblood oxbrake oxgates oxheart oxidase oxidate oxidize oxyacid oxysalt ozonide ozonize

8 letter words beginning with o:

oarlocks obdurate obedient obelisks obituary oblation obligate obligato obliging obligors oblivion observer obsidian obsolete obstacle obstruct obturate obtusity obvolute occamies occasion occident occision occupant occupier occurred oceanous ochidore ockerism oconnell ocotillo octangle octarchy octobass octofoil octonary octopine octoroon octuples octuplet odalborn oddballs odically odometer odontoid oecology oeillade oenocyte oestriol oestrone offering

official offprint offshoot offshore offstage offtrack ogenetic ohmmeter oilcloth oileries oilstone ointment okanagan okolehao okshoofd oldening oleander oleaster olibanum oligarch oliguria olivinic ollenite ological olykoeks omission omnified omnivore omphalos oncology oncoming onhanger onlooker onrushes ontogeny ontology oocyesis oocystic oogonium oosphere opalesce opdalite openband openbeak openings openwork operable operancy operated operatic operator opercula operetta ophidian ophionid opinicus opiumism oppilate opponent opposite

oppossum opposure opsonize optician optimism optimist optimize optional opulence opulency opuscule oracular orangery orariums oratorio orbiteer orbitude orcheses orchitis ordained ordalium orderers ordinals ordinand ordinary ordinate ordnance organdie organism organist organize orgulous oriental orifices original orinasal orlewise ornament ornithic orometer oropesas orpiment orreries orthicon orthodox orthoepy orthosis oryzenin oscitant oscitate osculate ossature ossified osteitis osteoids osteoses ostracod ostracon

otologic otoscope otosteon ouguiyas outbaked outbbled outbless outboard outbound outboxes outbrave outbreak outbreed outbully outburns outburst outcaste outclass outclomb outcoach outcomer outcries outcross outcured outcurve outdated outdoers outdoors outdwelt outedges outfield outfight outflank outfront outgoing outguard outguess outhired outhouse outlabor outlance outlawry outleaps outlines outlooks outlying outmarch outmoded outpiped outplans outpoint outpolls outpupil outrange outreach outrider outright outshine outshoot

outshout outsider outsizes outskate outslang outsleep outsmart outspeak outstand outstare outstole outstrip outstunt outswung outtaken outtalks outthink outvigil outvying outwards outweeds outweigh outwrung outyelps ovaritis ovenbird ovenpeel ovenware overable overaged overalls overarch overbear overbite overbold overbray overcast overcoat overcome overcraw overcrop overcull overdeep overdone overdoor overdose overdraw overdyes overfear overfeed overfile overfill overflow overgave overgoad overgrow overhand

overhang overhard overhaul overhead overhear overheat overkill overlaid overland overleap overline overling overlive overload overlock overlong overlook overlord overloup overlush overmast overmuch overnets overnice overpass overpert overpick overplay overplow overplus overpray overpuff overrate override overriot overripe overrule overseam overseas overseer oversell oversews overshoe overside oversize oversnow oversold oversoul overstay overstep oversway overtake overtare overtask overtime overtire overtone

overtook overture overturn overtype overused overview overwhip overwind overword overwork oviposit ovoplasm owlishly oxazepam oxharrow oxidants oxpecker oxycrate oxyfatty oxymoron oxytocic oxytocin oxyurous oystrige ozonates

9 letter words beginning with o:

oariocele oarswoman obbligato obcordate obeahisms obedience obeisance obfuscate objectify objection objective objectize objurgate obliquely obliquity oblivious obnoxiety obnoxious obovately obreption obscenely obscenity obscurant obscuring obscurity obsecrate obsequent obsequial obsequies obsequium observant obsession obsessive obsigning obsolesce obstetric obstinacy obstinate obstruent obtaining obtrusive obtundity obumbrate obversion occipital occlusion occlusive occultism occupable occupancy occupiers

occursive ockerisms ocotillos octachord octaechos octagonal octameter octaploid octastyle octennial octillion octohedra octoploid ocypodian odalisque odorizers odorosity oenochoae oestrogen offenders offensive offertory offhanded officered officiant officiary officiate officinal officious offshoots offspring oftwhiles ohmmeters oilfields oilpapers oldermost oleaceous olecranon oleograph oleoresin olfaction olfactive olfactory oligarchy oligomery oligopoly oliphants olivenite ombrifuge ombudsman ommatidia omnifidel omnihuman omnirange omophagia oncologic ondometer

onenesses onionskin onomantia onomastic onslaught ontogenal oogametes oogenesis ooplasmic opacifier operation operculum ophiolite ophiology ophiurids opiniater opiomania opportune opposable oppugnant opsisform opsonogen optimises optimizer optometer optometry opuntioid orangeade orangeman orangutan orationer oratorium orbicular orchestra orderings ordinable ordinance ordinates organelle organised organizer organotin organzine orgiastic orientate orienteer oriflamme origanums originate orillions ornithine orography orphanage orphandom orphaning orthodome orthodoxy orthoepic

orthopnea orthopter orthoptic orvietite oscheitis oscillate oscitancy osculates osmateria osmometer osmometry ossifrage ostensive ostensory osteology osteopath osteotome osteotomy ostiaries ostracism ostracize otherness otherwise otoconite otoconium otolithic otoplasty otopyosis oubliette ourselves outbounds outbuying outclamor outdances outdesign outdodges outdwells outechoed outermost outfables outfacing outfences outfitter outfloats outgained outgasses outgiving outglared outgnawed outgoings outgrowth outhiring outjinxed outjuggle outlander outlasted outlaying outlustre outnumber

outpicket outpowers outprayed outpushed outreason outroared outscored outscream outshadow outskirts outspoken outspread outstroke outstrove outsulked outsweeps outthrust outvaunts outwarble outwardly outwarred outweight outwicked outwindow outyelped ovenproof ovenwoods overacted overblame overbloom overblown overboard overbreed overbrows overbuild overburns overcanny overchase overcheck overclean overclear overcloud overdance overdecks overdoses overdraft overdress overdrily overdrive overdrove overdusts overeager overemote overexert

overglaze overhappy overhaste overhasty overhated overheaps overhonor overhotly overhover overissue overjawed overlarge overlends overloves overlying overmatch overmerry overnames overnight overnurse overobese overplaid overplain overplant overpower overprick overprint overprize overproof overreach overreact overripen overruled overscore overscour overseers overseing overshade overshave overshine overshoot oversides oversight oversizes overskirt oversleep overslide oversmite overspend overspill overstate overstock overstood overstudy overstuff oversweep oversweet overswing overtaken

overtempt overthrow overtrade overtrick overtrump overtures overtyped overurges overvalue overwater overweary overweigh overwhelm overwords overwrite overwrote oviparous ovotestis ownership ownwayish oxidation oxygenant oxygenate oxyhalide oxyhydric oysterman

10 letter words beginning with o:

oakenshaws oasthouses oathworthy obeisantly obfuscated obituarian obituarily obituarist obituarize objectival oblateness obligation obligatory obligingly obliterate obnubilate obsequence obsequious observable observance observanda observator obsidional obsignated obstetrics obstetricy obstructed obtainment obtrusions obturatory obvolution occasional occidental occultisms occupances occupating occupation occurrence oceanwards ochlocracy octaemeron octahedral octahedron octamerous octangular octaploids octastichs octavalent octodecimo octonarius octopushes

oculomotor odonatists odontalgia odontology odontomous oesophagus oestradiol offendable offendress offensives officerism officially oftentimes oktastylos oldfangled oleaginous olecranoid oligochete oligoclase oligohemia oligopsony oliguretic olivaceous olivescent ombrophile ombrophoby ommatidium omniactive omniformal omnilucent omnipotent omniranges omniregent omniscient omnivorous omophagias omphaloses oncolytics onomastics onomomancy onslaughts ontologism ontologist oostegitic opacifying opacimeter opalescent openhanded operagoers ophicleide ophiolater ophiolatry ophiomancy ophiophobe ophthalmia ophthalmic opotherapy

oppilation opposition oppression oppressive opprobrium optimistic optimizers optometers optophones orangewood oranginess orangutans oratorical orbiculate orchardist orchardman orchestral orchialgia orchidists ordainable ordinaries ordinarily ordination ordonnance organicism organogeny organology organozinc originable originally originates ornamental ornamented ornamenter ornithopod ornithosis orolingual orpheonist orthoclase orthogenic orthogonal orthopathy orthopedic orthoscope oscillator osculation osmolagnia osmotactic ossiferous osteectomy ostensible osteoblast osteoclast osteopathy osteophyte

osteosises othematoma otheoscope otherwhere otherwhile otherworld otological otopolypus otoscopies otosphenal outbalance outbatting outbitched outblossom outcharmed outclasses outcrosses outcursing outdressed outfielder outflatter outgeneral outgnawing outgunning outkissing outlandish outpatient outpouring outprodigy outputting outqueried outrageous outraignes outranking outrapping outreaches outreliefs outsavored outshining outskirter outsmiling outsported outstation outstretch outstriven outswelled outthunder outtongued outtrotted outtrumped outvenomed outwatches ovariocele

ovariotomy overabound overactive overblouse overbreeds overbulked overburden overcharge overcrammi overcredit overdrying overeaters overexcite overexpert overexpose overflight overflower overfrieze overgentle overgotten overgraded overgrowth overhailed overhating overheaped overhyping overiodize overlabors overlocked overlooker overmantel overmantle overmaster overmatter overmodest overnicety overpeered overpraise overpruned overracked overraught overriches overridden overriding overrigged oversailed oversanded overscream overseamer overseason overshadow overshirts overslaugh overspiced overspills overspread

overstared overstinks overstrain overstream overstrict overstride overstrung oversubtle oversubtly oversupply overtakers overtalked overtalker overtaxing overthinks overthrust overtrader overtumble overwealth overweener overweight overwinter overwisdom ovipositor oxdiacetic oxidimetry oxybenzoic oxybutyric oxycaproic oxycephaly oxychloric oxymoronic oxyuricide oysterlike ozonolysis ozonoscope

11 letter words beginning with o:

obediential objectifies objectivism objectivity obligedness obnubilated obscuration observation observatory obsolescent obsoletisms obstinately obstipation obstructing obstruction occultation oceanariums ochlophobia octahedrite octahydrate octennially octodentate octoradiate odometrical odontoblast odontocetes odontograph odontolcous odontophore odontoplast odontoscope odoriferous odorization oenophobist oesophagism offenseless offertories officialdom officialese officialism offsaddling oillessness olfactology oligistical oligochaete oligocholia oligopolies oligotrophy ombrophilic ommatophore omnifarious

omnipotence omnipresent omniscience omphalotomy oncologists oncosimeter oneiromancy onocentaurs onomatology ontologised onychomancy oophorotomy opacousness openmouthed operational operatrices operculated opiateproof opinionated opisthodome opportunism opportunist opportunity oppressible opprobrious optimalises optometries optometrist oracularity orbiculated orchestrate orchestrion ordainments organologic orientation originality ornithology ornithopter ornithosaur orpheoreons orthocaines orthocentre orthocymene orthodontia orthography orthopedias orthopedics orthopedist orthopteran orthoptists orthostichy

orthotomous orthotropic oscillation oscillators oscillatory oscillogram ostensorium ostentation osteoclasis osteodermis osteography osteopathic osteopedion ostracoderm ostracodous ostrichisms outbabbling outbreaking outbuilding outcropping outdistance outduelling outfeasting outfighting outfittings outflushing outgenerals outmaneuver outmatching outpourings outpraising outskipping outsleeping outspeeding outstanding outstations outstrained outstriding outstunting outtraveled outwarbling outwearying outwiggling ovariectomy overanxious overapplaud overarching overassumed overbalance overbearing overblowing overboiling overbooking overbooming overbreathe overbridged

overcareful overcasting overcertify overchannel overcleaned overcleared overclothes overconsume overcooling overcrawing overculture overcurious overdeeming overdevelop overdiluted overdraught overdrifted overexposes overextreme overfasting overfearing overfishing overfrailty overfraught overgrassed overgrazing overgreatly overharvest overindulge overinsures overjumping overknowing overliberal overmagnify overmatched overmeasure overmeddled overmilking overneglect overnetting overnoveled overnursing overobesity overplotted overplusses overpratice overquarter overquickly overrepress overroasted overscratch overservile oversetting overshortly oversliding overspatter

overstoping overstretch overstrikes overstuffed oversupping overtasking overtowered overwarming overwatcher overweening overwilling overworking overwrought overzealous ovovitellin oxycephalic oxygenising oxyhydrogen ozoniferous ozonosphere

12 letter words beginning with o:

oafishnesses obdurateness obfuscations objurgations obliteration obmutescence obscurantism obstetrician obstreperous obtruncation occasionally occidentally occupational oceanography ochlocracies ochrocarpous octachloride octogenarian octosyllabic octosyllable officeholder officialized olericulture oligophagies oligophagous oligotrophic omnidistance omnipresence omniprudence oncogenicity oneirocritic oneirodynias onomasiology onomatopoeia oophorectomy oophoromania openhandedly ophichthyoid ophthalmagra ophthalmious ophthalmitis oppignerated opportunisms opprobriated oppugnancies opsonization optimistical optoacoustic optometrical orbiculately orbiculation

orchidaceous orchidectomy organicistic organization organography organophilic originalists orihyperbola orismologies ornithomancy ornithomimid orthoclastic orthodontics orthodontist orthogenesis orthogenetic orthopterous orthorhombic orthosilicic orthotropies orthotropous oscillograph oscilloscope osculatrixes ossification osteectomies osteofibroma osteogenesis osteomalacia osteoplastic osteoporosis otacousticon otherworldly otiorhynchid otiosenesses ouranophobia outdelivered outfieldsmen outglittered outmarriages outsourcings outstretched ovariolumbar ovateconical overaccurate overactivate overanalyzed overasserted overbragging overbrimming overbrowsing overbusyness overcautious overcharging overclassify

overclearing overcritical overcrowding overdaintily overdazzling overdebating overdecorate overdesirous overdiffused overdominant overdrainage overdraughts overdrinking overestimate overexposure overextended overflowings overfreights overfullness overglorious overgraining overgrasping overgrievous overidentify overinclined overindulged overinvested overlavishly overliterary overmagnetic overmalapert overmaturely overmeasured overmobilize overmodestly overmoisture overornament overpictured overpinching overpowering overprinting overpromptly overrashness overreachers overrefining overremissly overreported overreserved overresponds overrestrain overrudeness oversecuring overseership overshoulder oversilently oversleeping oversteadily

overstocking overstrictly overstriding oversubtlety oversupplies overtaxation overtimbered overtimidity overtrimming overutilized overwearying overwhelming overwildness overyouthful oxalidaceous oxyacetylene oxychromatin oxymethylene oxynaphthoic ozonospheres

13 letter words beginning with o:

objectionable objectionably objectization obsolescently obstetricians obstreperates obtrusiveness obtusilingual occasionalism octodecillion odontologists odoriferously oleomargarine oligosiderite omnicredulous ontologically onychomalacia openendedness ophthalmalgic ophthalmolith ophthalmology oppositionist oppositipolar opprobriously opthalmoplegy orchestrating orchidologist organoarsenic organogenesis organomercury organotherapy orientalizing ornamentality ornamentation ornithischian ornithivorous ornithomorphs ornithoscopic orthocephalic orthoceratoid orthognathous orthographize orthohydrogen orthopaedists orthotoluidin orthovanadate osteoblastoma osteographies osteomalacias osteomyelitis osteopathists

osteopetroses outdelivering outfangthiefs outorganizing outpopulating outtyrannized overabundance overaddiction overanalyzing overasserting overassessing overbreathing overcautioned overcivilized overcolouring overconcerned overconstruct overconsuming overcrowdings overdecadence overdecorated overdiffusely overdocuments overdogmatism overdramatize overelaborate overexertedly overexposures overextending overeyebrowed overforwardly overfulnesses overgreatness overheaviness overidealized overinflation overissuances overlengthens overlordships overmobilized overmortgaged overmultitude overnourishes overnutrition overoffensive overpainfully overpensively overplausibly overplenitude overpraticing overpreoccupy

overreliances overrighteous overrigidness overscrubbing oversecretion oversubscribe overtaxations overvariation overweeningly overwrestling ovoviviparity ovoviviparous oystercatcher

14 letter words beginning with o:

obstructionist occidentalised oculopupillary oculozygomatic odonatologists odontoglossums omphaloskepsis omphalospinous onomatological operculigenous ophthalmoscope ophthalmoscopy oppositenesses organizational organographist organometallic ornithischians ornithomorphic orobanchaceous orthochromatic orthodiagraphy orthogonalized orthopinakoids osphresiologic osteoarthritis osteochondrous otoblennorrhea otolaryngology outdaciousness outsparspruing outtyrannizing overabsorption overabstemious overassumptive overburdensome overcapitalize overcommitting overcontribute overcorruption overdebilitate overdescribing overdevoutness overelliptical overemphatical overencourages overfactiously overfastidious overfierceness overfloridness overfrequently overhonestness

overinsistence overinsistency overinsolently overinterested overjoyfulness overmagnifying overmodernized overmoralistic overneutralize overornamented overpositively overpowerfully overpracticing overpressuring overprosperity overrefinement overreflection oversaturating overscrupulous oversevereness overspecialise overstraighten oxycalorimeter oxyhaemoglobin oxyluminescent

15 letter words beginning with o:

obtainabilities ochlocratically odontochirurgic olericulturally oligosaccharide ombudswomanship omnicompetences omnidirectional oophorectomized openheartedness ophthalmography ophthalmologist opisthognathous opisthorchiasis opticopupillary orchioneuralgia ornithorhynchus orthographizing orthopsychiatry osphresiolagnia osteothrombosis overabusiveness overattentively overbookishness overbrilliantly overcalculation overcourteously overdeliciously overdemandiness overdependences overdescriptive overdiscouraged overembellished overentertained overfearfulness overhomogenized overimpressibly overinfluential overinstruction overinstructive overlightheaded overmultituding overnormalizing overoffensively overorchestrate overpessimistic overpopulations overprominently overpronouncing oversententious overspecialized

oversubscribing oxytetracycline

16 letter words beginning with o:

objectionability objectlessnesses obsequiousnesses omnibenevolences ophthalmological ophthalmomalacia orthopsychiatric osteoarthritises osteosarcomatous overassumptively overcapitalising overcompensation overcomplacently overcriticalness overdelicateness overdenunciation overderisiveness overdevelopments overelliptically overenthusiastic overhomogenizing overinterference overmercifulness overnumerousness overornamentally overrationalized oversystematized oxyanthraquinone

17 letter words beginning with o:

occipitocalcarine occlusocervically oophorocystectomy openmouthednesses opportunistically osteohalisteresis overbounteousness overcompensations overcompetitively overconcentrating overexaggerations overexuberantness overfavorableness overornamentality overpatriotically overplentifulness overpreoccupation overpsychologized overreligiousness oversqueamishness oversystematizing

18 letter words beginning with o:

obstreperousnesses ophthalmotonometer ophthalmotonometry orchidocelioplasty orthopsychiatrists oscillographically ostentatiousnesses ovariohysterectomy overabstemiousness overaggressiveness overinterestedness overmultiplication overprotectiveness overrepresentation oversolidification oversophistication

19 letter words beginning with o:

otorhinolaryngology overcentralizations overindividualistic

20 letter words beginning with o:

ophthalmodynamometer overaggressivenesses overenthusiastically

23 letter words beginning with o:


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