English Words: O
15,494 words · Page 30 of 310
A set of eight works of art that are connected, and that can be seen either as a single work or as eight individual works. They are commonly found in literature, film, or video games.
Eight methylene groups in a molecule (typically in a row, with substituents or functional groups at each end)
An odorless organophosphate insecticide, C₈H₂₄N₄O₃P₂, that has also been used to treat myasthenia gravis.
Any of the eighteen isomeric aliphatic hydrocarbons (C₈H₁₈) found in petroleum, especially an iso-octane 2,2,4 trimethyl-pentane; they are used as fuels and solvents.
Any of several isomeric diketones, derived from octane, that are used as intermediates in organic synthesis
A high explosive derived from cubane, and one of the most powerful chemical explosives known.
A small circumpolar constellation of the southern sky, said to resemble an octant. It lies closest to the southern celestial pole of any constellation.
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 30. 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.