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.

514 wordsTop pick ORGANIZATIONSHighest score OBJECTIVIZING 37

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 514 · most-used 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

Showing the top 48 of 514 words. See every valid word

All valid words 514

A to Z. Includes rare and Collins-only words. Linked tiles open the word's meaning, score and rhymes.

  • 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
Letters by positionIn 48% of these words the 3rd letter is E.
2nd letter
  1. V44%
  2. R13%
  3. B8%
3rd letter
  1. E48%
  2. T17%
  3. C5%
4th letter
  1. R48%
  2. I10%
  3. H7%
11th letter
  1. I40%
  2. S11%
  3. E8%
12th letter
  1. E28%
  2. N24%
  3. S8%
13th letter
  1. S39%
  2. G17%
  3. D10%

Highest-scoring words

Scrabble and Words With Friends points, before board bonuses
Score spreadMost of these words score 19 in Scrabble; OBJECTIVIZING tops the list with 37. Scores before board bonuses.
  1. 1313 points: 3 words
  2. 14 points: 6 words
  3. 1515 points: 30 words
  4. 16 points: 15 words
  5. 1717 points: 57 words
  6. 18 points: 64 words
  7. 1919 points: 76 words
  8. 20 points: 57 words
  9. 2121 points: 45 words
  10. 22 points: 44 words
  11. 2323 points: 33 words
  12. 24 points: 19 words
  13. 2525 points: 15 words
  14. 26 points: 15 words
  15. 2727 points: 15 words
  16. 28 points: 9 words
  17. 2929 points: 6 words
  18. 30 points: 0 words
  19. 3131 points: 2 words
  20. 32 points: 1 words
  21. 3333 points: 0 words
  22. 34 points: 1 words
  23. 3535 points: 0 words
  24. 36 points: 0 words
  25. 3737 points: 1 words
WordScrabbleWords With FriendsDictionaries
OBJECTIVIZING3744Collins · NWL
OXYRHYNCHUSES3433Collins only
OVEREMPHASIZE3234All three
OXYHEMOGLOBIN3134All three
OVERCIVILIZED3135All three
OVERQUALIFIED2932All three
OVERANALYZING2933All three
OBJECTIONABLY2935All three
OBJECTIVISTIC2935All three
OVERBEJEWELED2934All three
OVEREXCITEDLY2931NWL only
ORTHOPYROXENE2828Collins 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

How many 13-letter words start with O?
There are 514 13-letter words starting with O in the tournament-dictionary collections used here. Examples include organizations, opportunities, observational, and orchestration. The total includes words found in at least one of the included lists, so a particular game may accept fewer.
What is the highest-scoring 13-letter word starting with O?
Objectivizing is the highest-scoring example, at 37 points. Oxyrhynchuses scores 34, and overemphasize scores 32. Those are tile scores before any board bonuses; your final result depends on where the word lands and which scoring rules your game uses.
Which ending is most common for 13-letter O words?
S is the most common final letter, appearing on 199 entries. G comes next with 87, followed by D with 51 and Y with 50. If your puzzle already fixes the last letter, checking S first gives you the largest group to search.

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