1. The battle cry of the US Marines.
2. A positive affirmation to any order or request.
3. An agreement to an order.
4. Used as a greeting or confirmation.
5. An adjective to describe something that is rugged and hardy in nature.
Sgt.: Do you Jarheads get me?
Platoon: Ooh rah sir!
Sgt.: Lets waste some Iraqi motherfuckers!
Platoon: Ooh rah!
That’s one ooh rah Marine.