Meaning of O in English

1. n. (also o) (pl. Os or O's)

1. the fifteenth letter of the alphabet.

2 (0) nought, zero (in a sequence of numerals esp. when spoken).

3 a human blood type of the ABO system. 2. abbr. (also O.) Old. 3.

symb. Chem. the element oxygen. 4. int.

1. var. of OH(1).

2 prefixed to a name in the vocative (O God).

Etymology: ME, natural excl.

Oxford English vocab.      Оксфордский английский словарь.