O
noun /əʊ/
/əʊ/
(also o)
(plural Os, O’s, o’s
/əʊz/
/əʊz/
)- [countable, uncountable] the 15th letter of the English alphabet
- ‘Orange’ begins with (an) O/‘O’.
- used to mean ‘zero’ when saying phone numbers, etc.
- My number is six o double three (= 6033).
see also O grade, O level