Oorah

Oorah is a battle cry common in the United States Marine Corps since the mid-20th century.
Several anecdotes attributed the phrase to John R. Massaro's time as a gunnery sergeant in the Reconnaissance Company, 1st Marine Division, in the mid-1950s. Massaro and other Marines who trained aboard the submarine, beginning in 1949, used oorah in imitation of the vessel's klaxon horn. Others have attributed the phrase's popularization to Massaro's subsequent time at Marine Corps Recruit Depot San Diego, where use of the word spread.
Massaro has said that he did not originate the word and that the word was already in use in 1949.