English Words: O
15,494 words · Page 136 of 310
A telescope with a diagonal eyepiece, suspended vertically in gimbals by the object end beneath a fixed diagonal plane mirror. It is used for delineating landscapes by means of an attached pencil.
A member of the patrician ruling class in republican Ancient Rome; an aristocrat, a noble.
A student who graduates with second class ("senior optime") or third class ("junior optime") honours in mathematics, or (loosely) in any other subject.
The design and operation of a system or process to make it as good as possible in some defined sense.
To omit (some portion of program logic) through optimization, when it is found to be unused or unnecessary.
A person in a large business whose task is to maximize profits and make the business more efficient.
The best or most favorable condition, or the greatest amount or degree possible under specific sets of comparable circumstances.
An action (or series of actions) that, when performed, automatically selects a preferred outcome of several possible outcomes, depending on the actions of other actors.
Of or pertaining to options on a stock or equity. For some stocks, it is possible to trade options on them, hence they are optionable, for other stocks options aren't traded so they are not optionable.
The value of additional optional investment opportunities available only after having made an initial investment.
To make optional; to add as an option, permit to be optionally omitted, or provide various options for implementing.
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 136. 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.