English Words: O
15,494 words · Page 135 of 310
In Ancient Greek cuisine, delicacies such as cooked fish, considered an integral component of a meal.
Any chemical produced by the body, including antibodies and complement proteins, that causes a pathogen to be more susceptible to phagocytosis.
The property of having to choose explicitly to join or permit something; a decision having the default option being exclusion or avoidance; used particularly with regard to mailing lists and advertising.
An electromechanical device that selectively raises small rods over the darker parts of a document, and thus enables blind people to read printed material that has not been transcribed into Braille.
A person who lives in a region undergoing a change of sovereignty and thus may choose between retaining their old citizenship or opting for the citizenship of the new sovereignty.
A stand which can hold one or more inverted bottles of alcohol fitted with optics, and which facilitates the serving of spirits.
Astronomy using observations using telescopes and recording media that capture visible light.
The electronic identification and digital encoding of printed or handwritten characters by means of an optical scanner and specialized software.
A vision or image that is deceptive or misleading, such as an optical illusion or a trick of the light.
The natural logarithm of the ratio of amount of radiation that hits an object to the amount of radiation that emerges from that object on the other side.
A class of glass used to create optical lenses, such as that for spectacles or spyglasses
An instrument, used both for recreational and scientific purposes, which provides a magnified view of distant objects by collecting and focusing light by means of mirrors and/or optical lenses.
An input device consisting of a small surface with an optical sensor, integrated for some smartphones and subnotebooks.
A scientific instrument that uses a highly focused laser beam to hold and move the microscopic or smaller objects such as atoms and droplets, in a manner similar to tweezers.
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 135. 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.