English Words: O
15,494 words · Page 309 of 310
A defensive gland present in some arthropods, which secretes a foul-smelling substance to discourage predators.
An atrophic type of chronic non-specific rhinitis characterized by a foul odor from the nose, now considered rare.
A baby resulting from an unplanned pregnancy while taking the weight loss drug Ozempic.
The sagging and aging of facial skin that occurs after rapid weight loss, often from taking Ozempic.
Of or relating to the fictional Land of Oz, introduced in the book The Wonderful Wizard of Oz (1900) by L. Frank Baum.
An inhabitant of the fictional Land of Oz, introduced in the book The Wonderful Wizard of Oz (1900) by L. Frank Baum.
A device that produces a supply of ozone by passing a silent electrical discharge through oxygen
An allotrope of oxygen (symbol O₃) having three atoms in the molecule instead of the usual two; it is a toxic gas, generated from oxygen by electrical discharge.
A region of the stratosphere over Antarctica (and a smaller one over the Arctic) that is depleted of ozone in the local spring.
A region of the stratosphere, between 15 and 30 kilometres in altitude, containing a relatively high concentration of ozone, which absorbs most solar ultraviolet radiation.
An instrument, carried aloft in a balloon, that measures the atmospheric concentration of ozone (and often other gases) and transmits the data by radio.
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 309. 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.