o

1. noun /əʊ,oʊ/

A zero .

2. interjection /əʊ,oʊ/

a) (always capitalized) The English vocative particle, used before a pronoun or the name of a person or persons to mark direct address.

O foolish Galatians, who hath bewitched you, that ye should not obey the truth, before whose eyes Jesus Christ hath been evidently set forth, crucified among you? Galatians 3:1 (King James version).

b) Variant of oh.