13-letter words starting with O
There are 514 13-letter words starting with O, including familiar forms like organizations and less common terms like ornithologist.
4 of 514 are everyday words (1%). Mostly rare words: great for Scrabble, tough for daily puzzles.
P starts the most 13-letter words (1,597); Y starts the fewest (10). O ranks #13 of 26. The bar under each letter shows the size of its list.
Best words to play first
- ORGANIZATIONS23
- OPPORTUNITIES17
- ORGANISATIONS14
- OBSERVATIONAL18
- OBJECTIONABLE26
- OPPORTUNISTIC19
- OPHTHALMOLOGY27
- OCEANOGRAPHIC23
- ORNAMENTATION15
- OVERESTIMATED19
- ORCHESTRATION18
- OPERATIONALLY18
- OBSERVATORIES18
- ORCHESTRATING19
- OPTIMIZATIONS26
- OBSTETRICIANS17
- OVERSTATEMENT18
- OUTPERFORMING21
- OVERCONFIDENT22
- OVERSHADOWING24
- OUTSTANDINGLY18
- OVERABUNDANCE21
- OCEANOGRAPHER21
- ORNITHOLOGIST17
- OVERPOPULATED21
- OVERQUALIFIED29
- OVERWINTERING20
- OFFICEHOLDERS25
- OVERSTRETCHED22
- OSTEOMYELITIS18
- OVERESTIMATES18
- OROPHARYNGEAL22
- OUTMANEUVERED19
- OVERSENSITIVE19
- OVERACHIEVING25
- OVERSATURATED17
- OFFENSIVENESS22
- ONTOLOGICALLY19
- ORTHODONTISTS17
- OVERDEVELOPED23
- OSCILLOSCOPES19
- OUTSPOKENNESS19
- OVERACHIEVERS24
- OBLIVIOUSNESS18
- ORTHOGONALITY20
- OVERVALUATION19
- ORGANOGENESIS15
- OVEREMPHASIZE32
All valid words 514
- OBJECTIONABLE26
- OBJECTIONABLY29
- OBJECTIVATING28
- OBJECTIVATION27
- OBJECTIVENESS27
- OBJECTIVISING28
- OBJECTIVISTIC29
- OBJECTIVITIES27
- OBJECTIVIZING37
- OBLIQUENESSES24
- OBLITERATIONS15
- OBLIVIOUSNESS18
- OBLIVISCENCES22
- OBMUTESCENCES21
- OBNOXIOUSNESS22
- OBNUBILATIONS17
- OBSCENENESSES17
- OBSCURANTISMS19
- OBSCURANTISTS17
- OBSCURENESSES17
- OBSERVABILITY23
- OBSERVATIONAL18
- OBSERVATORIES18
- OBSESSIONALLY18
- OBSESSIONISTS15
- OBSESSIVENESS18
- OBSOLESCENCES19
- OBSOLESCENTLY20
- OBSTETRICALLY20
- OBSTETRICIANS17
- OBSTINATENESS15
- OBSTREPERATED18
- OBSTREPERATES17
- OBSTRUCTIONAL17
- OBSTRUCTIVELY23
- OBTAINABILITY20
- OBTEMPERATING20
- OBTRUSIVENESS18
- OBVIOUSNESSES18
- OCCASIONALISM19
- OCCASIONALIST17
- OCCASIONALITY20
- OCCIDENTALISE18
- OCCIDENTALISM20
- OCCIDENTALIST18
- OCCIDENTALIZE27
- OCCLUSIVENESS20
- OCEANOGRAPHER21
- OCEANOGRAPHIC23
- OCEANOLOGICAL18
- OCEANOLOGISTS16
- OCHLOCRATICAL22
- OCHLOPHOBIACS27
- OCTINGENARIES16
- OCTOCENTENARY20
- OCTODECILLION18
- OCTOGENARIANS16
- OCTOSYLLABICS22
- OCTOSYLLABLES20
- ODONATOLOGIES15
- ODONATOLOGIST15
- ODONTOBLASTIC18
- ODONTOGLOSSUM17
- ODONTOLOGICAL17
- ODONTOLOGISTS15
- ODONTOPHOBIAS21
- ODONTOPHOROUS19
- ODONTORNITHES17
- ODORIFEROUSLY20
- ODOROUSNESSES14
- OECOLOGICALLY21
- OECUMENICALLY22
- OFFENSIVENESS22
- OFFHANDEDNESS24
- OFFICEHOLDERS25
- OFFICIALITIES21
- OFFICIOUSNESS21
- OLEANDOMYCINS21
- OLEOMARGARINE16
- OLEOMARGARINS16
- OLERICULTURES15
- OLFACTOLOGIES19
- OLFACTOLOGIST19
- OLFACTOMETERS20
- OLIGOPEPTIDES19
- OLIGOPOLISTIC18
- OLIGOSPERMIAS18
- OLIGOTROPHIES19
- OMBUDSMANSHIP25
- OMBUDSPERSONS20
- OMINOUSNESSES15
- OMMATOPHOROUS22
- OMNICOMPETENT21
- OMNIFARIOUSLY21
- OMNIFORMITIES20
- OMNIPOTENCIES19
- OMNIPRESENCES19
- OMNISEXUALITY25
- OMOPLATOSCOPY24
- ONEIROCRITICS17
- ONEIROMANCERS17
- ONEIROMANCIES17
- ONEIROSCOPIES17
- ONEIROSCOPIST17
- ONEROUSNESSES13
- ONGOINGNESSES15
- ONOMASTICALLY20
- ONOMASTICIANS17
- ONOMATOLOGIES16
- ONOMATOLOGIST16
- ONOMATOPOEIAS17
- ONOMATOPOESES17
- ONOMATOPOESIS17
- ONOMATOPOETIC19
- ONTOGENICALLY19
- ONTOLOGICALLY19
- ONYCHOMANCIES25
- ONYCHOPHAGIES27
- ONYCHOPHAGIST27
- ONYCHOPHORANS26
- OPACIFICATION22
- OPENABILITIES17
- OPENHEARTEDLY22
- OPENMOUTHEDLY24
- OPERABILITIES17
- OPERATIONALLY18
- OPERATIONISMS17
- OPERATIONISTS15
- OPERATIVENESS18
- OPERATIVITIES18
- OPEROSENESSES15
- OPHIDIOPHOBES26
- OPHIDIOPHOBIA26
- OPHIDIOPHOBIC28
- OPHIOMORPHOUS25
- OPHIOPHILISTS23
- OPHTHALMOLOGY27
- OPINIONATEDLY19
- OPISTHOBRANCH25
- OPISTHOGRAPHS24
- OPISTHOGRAPHY27
- OPISTHOSOMATA20
- OPPIGNERATING19
- OPPIGNORATING19
- OPPIGNORATION18
- OPPORTUNENESS17
- OPPORTUNISTIC19
- OPPORTUNITIES17
- OPPOSITIONIST17
- OPPROBRIOUSLY22
- OPSONISATIONS15
- OPSONIZATIONS24
- OPTIMISATIONS17
- OPTIMIZATIONS26
- OPTIONALITIES15
- ORACULARITIES15
- ORACULOUSNESS15
- ORCHESOGRAPHY27
- ORCHESTRALIST18
- ORCHESTRATERS18
- ORCHESTRATING19
- ORCHESTRATION18
- ORCHESTRATORS18
- ORCHIDOLOGIES20
- ORCHIDOLOGIST20
- ORCHIDOMANIAC23
- ORCHIDOMANIAS21
- ORCHIECTOMIES22
- ORDERLINESSES14
- OREOGRAPHICAL21
- ORGANISATIONS14
- ORGANIZATIONS23
- ORGANOGENESES15
- ORGANOGENESIS15
- ORGANOGENETIC17
- ORGANOGRAPHIC22
- ORGANOLOGICAL17
- ORGANOLOGISTS15
- ORGANOTHERAPY22
- ORGIASTICALLY19
- ORIENTALISING14
- ORIENTALITIES13
- ORIENTALIZING23
- ORIENTATIONAL13
- ORIENTEERINGS14
- ORIGINALITIES14
- ORIGINATIVELY20
- ORISMOLOGICAL18
- ORNAMENTALISM17
- ORNAMENTATION15
- ORNITHICHNITE21
- ORNITHISCHIAN21
- ORNITHOGALUMS19
- ORNITHOLOGIES17
- ORNITHOLOGIST17
- ORNITHOMANTIC20
- ORNITHOMORPHS23
- ORNITHOPHOBIA23
- OROPHARYNGEAL22
- ORTHOCEPHALIC25
- ORTHODIAGONAL18
- ORTHODONTISTS17
- ORTHOEPICALLY23
- ORTHOGNATHIES20
- ORTHOGNATHISM22
- ORTHOGNATHOUS20
- ORTHOGONALISE17
- ORTHOGONALITY20
- ORTHOGONALIZE26
- ORTHOGRAPHERS22
- ORTHOGRAPHIES22
- ORTHOGRAPHIST22
- ORTHOHYDROGEN24
- ORTHOPAEDICAL21
- ORTHOPAEDISTS19
- ORTHOPINAKOID23
- ORTHOPTERISTS18
- ORTHOPTEROIDS19
- ORTHOPYROXENE28
- ORTHOSILICATE18
- ORTHOSTICHIES21
- ORTHOSTICHOUS21
- ORTHOTROPISMS20
- ORTHOTUNGSTIC19
- OSCILLATIONAL15
- OSCILLOGRAPHS21
- OSCILLOGRAPHY24
- OSCILLOSCOPES19
- OSCILLOSCOPIC21
- OSSIFICATIONS18
- OSTEICHTHYANS24
- OSTENSIBILITY18
- OSTEOFIBROSES18
- OSTEOFIBROSIS18
- OSTEOGRAPHIES19
- OSTEOMALACIAL17
- OSTEOMALACIAS17
- OSTEOMYELITIS18
- OSTEOPATHISTS18
- OSTEOPETROSES15
- OSTEOPETROSIS15
- OSTEOPLASTIES15
- OSTEOSARCOMAS17
- OSTREICULTURE15
- OSTREOPHAGIES19
- OSTREOPHAGOUS19
- OTHERWORLDISH23
- OTOTOXICITIES22
- OUTBARGAINING17
- OUTBLUSTERING16
- OUTDELIVERING18
- OUTDISTANCING17
- OUTDOORSWOMAN19
- OUTDOORSWOMEN19
- OUTGENERALING15
- OUTGENERALLED15
- OUTGLITTERING15
- OUTINTRIGUING15
- OUTMANEUVERED19
- OUTMANIPULATE17
- OUTMANOEUVRED19
- OUTMANOEUVRES18
- OUTORGANISING15
- OUTORGANIZING24
- OUTPASSIONING16
- OUTPERFORMING21
- OUTPLACEMENTS19
- OUTPOLITICKED22
- OUTPOPULATING18
- OUTREBOUNDING17
- OUTRECUIDANCE18
- OUTREPRODUCED19
- OUTREPRODUCES18
- OUTSETTLEMENT15
- OUTSPOKENNESS19
- OUTSTANDINGLY18
- OUTSTRETCHING19
- OUTSWEETENING17
- OUTTRAVELLING17
- OUTVILLAINING17
- OUTWARDNESSES17
- OVARIECTOMIES20
- OVARIOTOMISTS18
- OVERABOUNDING20
- OVERABSTRACTS20
- OVERABUNDANCE21
- OVERACHIEVERS24
- OVERACHIEVING25
- OVERADJUSTING25
- OVERADVERTISE20
- OVERALERTNESS16
- OVERAMBITIOUS20
- OVERAMPLIFIED24
- OVERANALYSING20
- OVERANALYZING29
- OVERANXIETIES23
- OVERARRANGING18
- OVERASSERTING17
- OVERASSERTION16
- OVERASSERTIVE19
- OVERASSESSING17
- OVERATTENTION16
- OVERATTENTIVE19
- OVERBALANCING21
- OVERBEARINGLY22
- OVERBEJEWELED29
- OVERBLEACHING24
- OVERBORROWING22
- OVERBREATHING22
- OVERBUILDINGS20
- OVERBURDENING20
- OVERBURTHENED22
- OVERCANOPYING24
- OVERCAREFULLY24
- OVERCAUTIONED19
- OVERCIVILISED22
- OVERCIVILIZED31
- OVERCOLOURING19
- OVERCOMMITTED23
- OVERCONCERNED21
- OVERCONFIDENT22
- OVERCONSCIOUS20
- OVERCONSTRUCT20
- OVERCONSUMING21
- OVERCORRECTED21
- OVERCREDULITY22
- OVERCREDULOUS19
- OVERCROWDINGS23
- OVERDECORATED20
- OVERDECORATES19
- OVERDEMANDING21
- OVERDEPENDENT20
- OVERDESIGNING19
- OVERDETERMINE19
- OVERDEVELOPED23
- OVERDEVIATING21
- OVERDIAGNOSED19
- OVERDIAGNOSES18
- OVERDIAGNOSIS18
- OVERDIRECTING20
- OVERDISCOUNTS19
- OVERDIVERSITY23
- OVERDOCUMENTS21
- OVERDOMINANCE21
- OVERDRAMATICS21
- OVERDRAMATISE19
- OVERDRAMATIZE28
- OVEREAGERNESS17
- OVEREARNESTLY19
- OVEREDUCATING20
- OVEREDUCATION19
- OVERELABORATE18
- OVEREMBELLISH23
- OVEREMOTIONAL18
- OVEREMPHASISE23
- OVEREMPHASIZE32
- OVERENAMOURED19
- OVERENCOURAGE19
- OVERENERGETIC19
- OVERENGINEERS17
- OVERESTIMATED19
- OVERESTIMATES18
- OVEREVALUATED20
- OVEREVALUATES19
- OVEREXCITABLE27
- OVEREXCITEDLY29
- OVEREXERCISED26
- OVEREXERCISES25
- OVEREXERTIONS23
- OVEREXPANDING27
- OVEREXPANSION25
- OVEREXPLAINED26
- OVEREXPLOITED26
- OVEREXPOSURES25
- OVEREXTENDING25
- OVEREXTENSION23
- OVEREXUBERANT25
- OVERFATIGUING21
- OVERFERTILISE19
- OVERFERTILIZE28
- OVERFLOWINGLY26
- OVERFOCUSSING22
- OVERFULFILLED23
- OVERFULNESSES19
- OVERGLAMORISE19
- OVERGLAMORIZE28
- OVERGOVERNING21
- OVERHARVESTED23
- OVERHASTINESS19
- OVERIDEALISED18
- OVERIDEALISES17
- OVERIDEALIZED27
- OVERIDEALIZES26
- OVERIMPRESSED21
- OVERIMPRESSES20
- OVERINDULGENT18
- OVERINDULGING19
- OVERINFLATING20
- OVERINFLATION19
- OVERINFORMING22
- OVERINGENIOUS17
- OVERINGENUITY20
- OVERINSISTENT16
- OVERINSURANCE18
- OVERINTENSELY19
- OVERINTENSITY19
- OVERINTERPRET18
- OVERINVESTING20
- OVERISSUANCES18
- OVERLABOURING19
- OVERLAUNCHING22
- OVERLAVISHING23
- OVERLEAVENING20
- OVERLENGTHENS20
- OVERLORDSHIPS22
- OVERMASTERING19
- OVERMEASURING19
- OVERMEDICATED22
- OVERMEDICATES21
- OVERMODESTIES19
- OVERMODULATED20
- OVERMULTITUDE19
- OVERNOURISHED20
- OVERNOURISHES19
- OVERNUTRITION16
- OVEROPERATING19
- OVEROPTIMISMS22
- OVEROPTIMISTS20
- OVERORGANISED18
- OVERORGANISES17
- OVERORGANIZED27
- OVERORGANIZES26
- OVERORNAMENTS18
- OVERPACKAGING26
- OVERPEDALLING20
- OVERPERSUADED20
- OVERPERSUADES19
- OVERPICTURING21
- OVERPOPULATED21
- OVERPOPULATES20
- OVERPREDICTED22
- OVERPREPARING21
- OVERPRESCRIBE22
- OVERPRESSURED19
- OVERPRESSURES18
- OVERPROCESSED21
- OVERPROCESSES20
- OVERPRODUCING22
- OVERPROGRAMED22
- OVERPROMISING21
- OVERPROMOTING21
- OVERPROTECTED21
- OVERQUALIFIED29
- OVERREACHINGS22
- OVERREACTIONS18
- OVERRECKONING23
- OVERREGULATED18
- OVERREGULATES17
- OVERRELIANCES18
- OVERREPORTING19
- OVERREPRESENT18
- OVERRESPONDED20
- OVERSAMPLINGS21
- OVERSATURATED17
- OVERSATURATES16
- OVERSCHEDULED23
- OVERSCHEDULES22
- OVERSECRETING19
- OVERSECRETION18
- OVERSENSITIVE19
- OVERSERIOUSLY19
- OVERSERVICING22
- OVERSHADOWING24
- OVERSHOWERING23
- OVERSLAUGHING21
- OVERSPECULATE20
- OVERSPREADING20
- OVERSTABILITY21
- OVERSTATEMENT18
- OVERSTIMULATE18
- OVERSTRAINING17
- OVERSTRESSING17
- OVERSTRETCHED22
- OVERSTRETCHES21
- OVERSTRUCTURE18
- OVERSUBSCRIBE22
- OVERSUPPLYING24
- OVERSWEETENED20
- OVERSWEETNESS19
- OVERTALKATIVE23
- OVERTAXATIONS23
- OVERTHWARTING23
- OVERTIGHTENED21
- OVERTREATMENT18
- OVERUTILISING17
- OVERUTILIZING26
- OVERVALUATION19
- OVERVIOLENTLY22
- OVERWEATHERED23
- OVERWEENINGLY23
- OVERWEIGHTING24
- OVERWHELMINGS25
- OVERWINTERING20
- OVERWITHHOLDS26
- OVERWRESTLING20
- OVERZEALOUSLY28
- OVIPOSITIONAL18
- OVOVIVIPARITY27
- OVOVIVIPAROUS24
- OXALOACETATES22
- OXYACETYLENES28
- OXYHEMOGLOBIN31
- OXYRHYNCHUSES34
- OYSTERCATCHER23
Highest-scoring words
| Word | Scrabble | Words With Friends | Dictionaries |
|---|---|---|---|
| OBJECTIVIZING | 37 | 44 | Collins · NWL |
| OXYRHYNCHUSES | 34 | 33 | Collins only |
| OVEREMPHASIZE | 32 | 34 | All three |
| OXYHEMOGLOBIN | 31 | 34 | All three |
| OVERCIVILIZED | 31 | 35 | All three |
| OVERQUALIFIED | 29 | 32 | All three |
| OVERANALYZING | 29 | 33 | All three |
| OBJECTIONABLY | 29 | 35 | All three |
| OBJECTIVISTIC | 29 | 35 | All three |
| OVERBEJEWELED | 29 | 34 | All three |
| OVEREXCITEDLY | 29 | 31 | NWL only |
| ORTHOPYROXENE | 28 | 28 | Collins only |
O has a substantial long-word list, but it trails the biggest starting letters: P has 1,597 13-letter entries, while O has 514. Just four O entries fall among the top 25,000 English words by frequency, so expect plenty of specialist vocabulary. The strongest entries for word games often come from unusual letter combinations rather than everyday usage.
13-letter words starting with O at a glance
- The list contains 514 words accepted by at least one tournament dictionary.
- The most common final letter is S, with 199 words; G is next with 87.
- Only four entries rank among the top 25,000 English words by frequency.
- Objectivizing leads the high-score examples at 37 points.
- The list includes 469 Collins words, compared with 363 in NWL2023.
Which O words score the most?
Objectivizing tops the scoring examples at 37 points. Oxyrhynchuses follows at 34, while overemphasize scores 32. These long plays combine less common letters with a useful spread of vowels and consonants, but the board matters: a premium square can change the result substantially.
Oxyhemoglobin and overcivilized each score 31, and overqualified scores 29. For a more recognizable option, objectionably also reaches 29. Treat these as strong tile-value candidates, not guaranteed plays; weigh your rack and the open board space before committing.
How can you narrow 13-letter O words?
Start with the ending when you have a fixed final letter: 199 entries end in S, far more than the 87 ending in G. That points toward plural forms such as organizations and observatories, alongside words ending in -ing, such as orchestrating. A known suffix can quickly cut down the search.
Then use familiar word families. Opportunities and opportunistic share a recognizable opening, while observational and oceanographic suggest academic or technical vocabulary.
Only four entries are common by the frequency measure, so many matches will feel specialized. The 514-word total combines several tournament dictionaries, not one universal game list; check your game's word list before playing.
Questions people ask
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