slang version of "oohrah!" used by marines to greet each other or express motivation or understanding of a task or briefing. usually used as false motivation when one of lower ranks is tasked with a gay task that nobody wants to do...
Sergeant: Hey PFC, go fill up those sandbags
PFC: Uhruh sergeant, kill babies!
Corporal: Hey PFC nice job on that log run today
PFC: Uhruh Corporal, thanks!