frag

M67 Fragmentation Hand Grenade, which was a replacement for the M61 grenade used during Vietnam and the older MK2 "Pineapple" grenade used since World War Two and well into the Vietnam War. [source here]

Fragging is a term from the Vietnam War, used primarily by U.S. military personnel, most commonly meaning to assassinate an unpopular officer of one's own fighting unit, often by means of a fragmentation grenade [hence the term].