| o' |
| O' | . [ Ir. o a descendant. ] A prefix to Irish family names, which signifies grandson or descendant of, and is a character of dignity; |
| O' | prep. A shortened form of of or on. “At the turning o' the tide.” Shak. [ 1913 Webster ] |
| O'er | prep. & adv. A contr. of Over. [ Poetic ] [ 1913 Webster ] |
| o'brien | (n) Irish writer (born in 1932), Syn. Edna O'Brien |
| o'casey | (n) Irish playwright (1880-1964), Syn. Sean O'Casey |
| o'clock | (adv) according to the clock, Example: it's three o'clock in Tokyo now |
| o'connor | (n) United States writer (1925-1964), Syn. Flannery O'Connor, Mary Flannery O'Connor |
| o'flaherty | (n) Irish writer of short stories (1896-1984), Syn. Liam O'Flaherty |
| o'hara | (n) United States writer (1905-1970), Syn. John Henry O'Hara |
| o'keeffe | (n) United States painter (1887-1986), Syn. Georgia Okeeffe |
| o'neill | (n) United States playwright (1888-1953), Syn. Eugene Gladstone O'Neill, Eugene O'Neill |
| o'toole | (n) British actor (born in Ireland in 1932), Syn. Peter Seamus O'Toole, Peter O'Toole |