- (prep.) A shortened form of of or on.
- A prefix to Irish family names, which signifies grandson or descendant of, and is a character of dignity; as, O'Neil, O'Carrol.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). o'. Retrieved September 21, 2026, from http://smartdefine.org/o%27/definitions/2037811 |
| Chicago | Webster's. 2011. "o'" http://smartdefine.org/o%27/definitions/2037811 (accessed September 21, 2026). |
| Harvard | Webster's 2011, o', Smart Define, viewed 21 September, 2026, <http://smartdefine.org/o%27/definitions/2037811>. |
| MLA | Webster's. "o'" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/o%27/definitions/2037811> |