o'

[ uh, oh ]
/ ə, oʊ /

preposition

an abbreviated form of of, as in o'clock or will-o'-the-wisp.
an abbreviated form of on.

Origin of o'

Middle English; by shortening.

Definition for o' (2 of 2)

O'

a prefix meaning “descendant,” in Irish family names: O'Brien; O'Connor.

Origin of O'

representing Irish ó descendant, Old Irish au

British Dictionary definitions for o'

o'
/ (ə) /

preposition

informal, or archaic shortened form of of a cup o' tea