AntrimAn‧trim /ˈæntrɪm/ 
1a former county in northeastern Northern Ireland → Ulster2a town in Northern Ireland
1a former county in northeastern Northern Ireland → Ulster2a town in Northern Ireland- operating room
- operating system
- operating table
- operating theatre
- operation
- operational
- operationally
- operational research
- Operation Desert Storm
- Operation Iraqi Freedom
- Operation Overlord
- operative
- operator
- operetta
- Ophelia
- ophthalmic
- ophthalmologist
- ophthalmology
- opiate
- opine
- opinion
- opinionated
- opinion-makers
- opinion poll
- opium