1 definition by JJNYC

Marine Corps response in the affirmative and as a cheer and to signify that a Marine is ready for action.

Started with Marine Amphibious units during the Korean War in 1953. Many Marines had to be delivered to shore by means of submarine. On US Submarines the klaxon alarm sounds when the vessel is about to dive with its classic "Aoogah" sound. When Marines on the submarine heard this distinctive sound it usually meant that they were about to go into battle on shore very soon. It soon became shortened to "Oorah" and signified that a Marine was battle-ready.
Are we going to accomplish this mission? Oorah, Sir!
by JJNYC November 18, 2007