- o
- oo1 or O [ō]n.pl. O's, o's1. the fifteenth letter of the English alphabet: from the Greek omega and omicron, both borrowed from the Phoenician2. any of the speech sounds that this letter represents, as, in English, the vowel (ō) of boat, (ä) of hot, or (ô) of wrong3. a type or impression for o or O4. the fifteenth in a sequence or group5. an object shaped like Oadj.1. of o or O2. fifteenth in a sequence or group3. shaped like O; circular or oval in shapeo2abbrev.1. octavo2. old3. only
English World dictionary. V. Neufeldt. 2014.