O.
The fifteenth letter of the English alphabet, called o and written in the Latin script.
Meaning & usage
The fifteenth letter of the English alphabet, called o and written in the Latin script.
Something shaped like the letter O.
A blood type that lacks A or B antigens and may only receive transfusions of similar type O blood, but may donate to all (neglecting Rh factor). Synonym: universal donor.
The fifteenth numeral symbol of the English alphabet, called o and written in the Latin script.
The vocative particle, used for direct address.
Where this word comes from
Etymology tree Latin ō Old French ohbor. Middle English o English O From Middle English O, o, from Old English o, from Latin o and Ancient Greek ὦ (ô, interjection). Featured prominently in William Tyndale's 1525 translation of the New Testament.
An utterance of the vocative O.
Where this word comes from
Etymology tree Latin ō Old French ohbor. Middle English o English O From Middle English O, o, from Old English o, from Latin o and Ancient Greek ὦ (ô, interjection). Featured prominently in William Tyndale's 1525 translation of the New Testament.
American Library Association abbreviation of octavo, a book size (20-25 cm).
Someone associated with Leyton Orient Football Club, as a player, coach, supporter etc.
The number of overs bowled.
Orgasm.
Opium.
Where this word comes from
Abbreviation.
A surname from Korean.
Where this word comes from
Korean 오(伍) (O) or 오(吳) (O). Doublet of Wu.
A surname from Mandarin Chinese.
Alternative form of E (Ancient Chinese Kingdom)
Where this word comes from
From Mandarin 鄂 (È) Wade–Giles romanization: O⁴.
With sugar and no condensed milk added.
Where this word comes from
From Hokkien 烏 /乌 (o͘, “black”) or Teochew 烏 /乌 (ou¹, “black”).
Abbreviation of morally offensive, film classification of the National Legion of Decency.
Abbreviation of Orthodox.
Where this word comes from
Abbreviation.
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Definitions, grammatical labels, IPA, etymology and examples: Wiktionary contributors, extracted by Kaikki / Wiktextract. Adapted under CC BY-SA 4.0. Selected fields and authored examples are shown; third-party quotations and audio are omitted. See contributor history.
Last enriched 2026-09-10. Definitions are in English. Romanizations are shown when supplied by the source; syllable estimates are omitted for unsupported scripts.