12 Letter Words Starting With O
There are 419 12-letter words starting with O, listed alphabetically below. Tap any word to see its definition, its score in Scrabble and Words With Friends, and the anagrams hiding inside it.
419 WORDS
oafishnesses18oarsmanships19obdurateness15obfuscations19objectifying30objectivisms28objectivists26objurgations22oblanceolate16oblatenesses14obligatorily18obligingness16obliterating15obliteration14obliterative17obliterators14obnubilating17obnubilation16obscurantism18obscurantist16obscurations16obsequiously26observations17obsolescence18obsoleteness14obstetrician16obstreperous16obstructions16obstructives19obtusenesses14occasionally19occidentally20occultations16occupational18oceanography23oceanologies15oceanologist15ochlocracies21octahedrally21octapeptides19octogenarian15octosyllabic21octosyllable19odiousnesses13odontoblasts15officeholder24officialdoms23officialeses20officialisms22officiations20offishnesses21offscourings21oleaginously16oleandomycin20oleoresinous12olfactometer19oligarchical20oligochaetes18oligophagies19oligophagous19oligopsonies15oligotrophic20omnipotences18omnipotently19omnipresence18omnisciences18omnisciently19omnivorously20oncogenicity20oncornavirus17onomastician16onomatopoeia16onomatopoeic18onychophoran25oophorectomy24opalescences18opalescently19opaquenesses23openhandedly22operatically19operationism16operationist14operatorless14opinionative17opportunisms18opportunists16opposability21oppositeness16oppositional16oppressively22optimalities16optimisation16optimization25optometrists16oratorically17orchestrally20orchestrated18orchestrater17orchestrates17orchestrator17orchidaceous20ordinariness13organicities15organisation13organization22organoleptic17organologies14orientalisms14orientalists12orientalized22orientalizes21orientations12orienteering13originations13orismologies15ornamentally17ornatenesses12ornerinesses12ornithologic18ornithopters17orographical20oropharynges21oropharynxes27orotundities13orthocenters17orthodontias16orthodontics18orthodontist16orthogeneses16orthogenesis16orthogenetic18orthogonally19orthographic23orthopaedics20orthopedists18orthopterans17orthopterist17orthopteroid18orthorhombic24orthotropous17oscillations14oscillograms17oscillograph20oscilloscope18osmolalities14osmolarities14ossification17ostentations12ostentatious12osteoblastic16osteoclastic16osteogeneses13osteogenesis13osteological15osteologists13osteomalacia16osteopathies17osteoplastic16osteoporoses14osteoporosis14osteoporotic16osteosarcoma16ostracoderms17otherworldly22otiosenesses12otoscleroses14otosclerosis14outachieving21outbalancing17outbargained16outbreedings16outbuildings16outcavilling18outcompeting19outcroppings19outdatedness14outdelivered17outdesigning15outdistanced16outdistances15outgeneraled14outglittered14outgoingness14outintrigued14outintrigues13outlandishly19outmaneuvers17outnumbering17outorganized23outorganizes22outperformed20outplacement18outpoliticks20outpopulated17outpopulates16outpreaching20outproducing18outpromising17outrageously16outrebounded16outreproduce17outrivalling16outsiderness13outsourcings15outsparkling19outspreading16outsprinting15outstretched18outstretches17outstripping17outthrobbing20outthrusting16outwrestling16ovariotomies17overabstract19overabundant18overachieved24overachiever23overachieves23overactivity23overanalyses18overanalysis18overanalyzed28overanalyzes27overarousals15overarranged17overarranges16overasserted16overbalanced20overbalances19overbleached23overbleaches22overborrowed21overbrowsing21overbuilding19overburdened19overcapacity24overcastings18overcautions17overcautious17overcharging22overchilling21overclaiming20overclassify23overcleaning18overclearing18overclouding19overcoaching23overcompress21overconcerns19overconsumed20overconsumes19overcontrols17overcorrects19overcounting18overcramming22overcritical19overcropping22overcrowding22overdecorate18overdesigned18overdevelops21overdirected19overdiscount18overdocument20overdominant18overdramatic20overdressing17overdrinking21overeducated19overeducates18overemphases22overemphasis22overemphatic24overenamored18overengineer16overenrolled16overequipped29overestimate17overexciting25overexercise24overexerting23overexertion22overexpanded26overexplains24overexplicit26overexploits24overexposing25overexposure24overextended24overfamiliar20overfatigued20overfatigues19overfavoring22overfocusing21overfocussed21overfocusses20overfulfills21overgarments18overgenerous16overgoverned20overhandling20overharvests21overhuntings19overidealize25overidentify22overindulged18overindulges17overinflated19overinflates18overinformed21overinsuring16overissuance17overlaboring18overlearning16overlengthen19overlighting20overliterary18overlordship21overmanaging19overmannered18overmastered18overmatching23overmaturity20overmedicate20overmodestly21overnighters19overnighting20overoperated18overoperates17overoptimism21overoptimist19overorganize25overornament17overpackaged25overpackages24overpayments22overpedaling19overpedalled19overpeopling20overpersuade18overplanning18overplanting18overplotting18overpopulate19overpowering21overpraising18overpressure17overprinting18overproduced21overproduces20overprograms20overpromised20overpromises19overpromoted20overpromotes19overprotects19overreachers20overreaching21overreacting18overreaction17overregulate16overreliance17overreported18overresponds18oversanguine16oversaturate15overserviced21overservices20overshadowed23overshooting19oversimplify25overslaughed20oversleeping18overslipping20overspenders18overspending19overstaffing22overstepping20overstirring16overstocking22overstrained16overstressed16overstresses15overstrewing19overstridden17overstriding17overstriking20overstuffing22oversupplied20oversupplies19oversweetens18overswinging20overtaxation22overthinking23overthrowing22overtightens19overtraining16overtreating16overtrimming20overtrumping20overutilized25overutilizes24overvoltages19overwatering19overweighing23overweighted23overwhelming24overwintered19overwithheld25overwithhold25ovipositions17owlishnesses18oxalacetates21oxaloacetate21oxyacetylene27oxygenations23ozonizations30ozonospheres26