English Words: O
15,494 words · Page 173 of 310
The restrictions a language applies to the positions and patterns of graphemes in written words.
The study of straight lines, especially in regards to the flight paths that UFOs tend to follow.
Any orthoester, formally derived from (the unstable) thioformic acid, of general formula HC(SR)₃
An organic compound with chemical formula (C₆H₄(CH₃)NH₂)₂, used mainly in dye production.
Retaining the accent; not enclitic; said of certain indefinite pronouns and adverbs when used interrogatively, which are enclitic in other situations.
an orthodontic method invented by John Mew which is claimed to be able to guide facial growth.
An orthorhombic-dipyramidal pale yellow mineral containing arsenic, bismuth, hydrogen, oxygen, and uranium.
An aromatic hydrocarbon based on benzene with two methyl substituents bonded to adjacent carbon atoms in the aromatic ring (the ortho configuration).
Spelling & Dictionary Insight
The English alphabetical index for the letter O contains 15,494 headwords drawn from our Wiktionary-derived dictionary table. At 50 entries per page the browse splits into 310 pages, and you are currently viewing page 173. Every row above is a dictionary-backed entry with a canonical slug, and each links through to a full definition page with pronunciation, senses, etymology, and related-word data where available.
On this page 50 of 50 entries carry a part-of-speech tag and 50 carry at least one stored definition. Coverage varies across letters because Wiktionary volunteers build entries at different speeds for different parts of the alphabet, letters with common starting sounds (S, C, T, P) usually have the densest coverage, while less frequent starters (X, Q, Z) tend to have shorter but more specialised lists. PlainSpell surfaces whatever data is present and links back to the source when a definition is not yet recorded.
For readers using this index as a spelling reference, the guarantee is that every form you see on the list is a documented English headword, not a guess, not a derived inflection lacking a lemma row. If a word you expected to find is absent from the "O" list, it usually means the form exists only as an inflection of another lemma (e.g. a past participle stored under the infinitive) or the entry has not yet been imported from Wiktionary. Use the search bar or the misspelling lookup to resolve these cases.