1 definition by PFC King

US Military terminology: the act of pointing the barrel of a firearm at another member of the US Military. Used especially during close-combat situations and during training.
During basic rifle marksmanship in basic training, a private got tackled for flagging a drill sergeant.

When clearing rooms, you must pay close attention to your muzzle so as to not flag your buddy.
by PFC King September 1, 2005
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