- (geographical) The northern province of Ireland, made up of all six Northern Irish counties and three counties in the Republic of Ireland.
- (politics, proscribed) The six counties that make up Northern Ireland.
Because the historical province of Ulster included parts of the present day Republic of Ireland as well as Northern Ireland, using it to refer only to Northern Ireland is imprecise and often proscribed.
Ulster (plural Ulsters)
- Alternative form of (men's heavy overcoat).
Ulster (not comparable)
- Relating to, or originating from Ulster.
- an Ulster fry