(v.) to plase a bullet into someone's buttox; usually done out of anger, fear, frustration, or as an act of self defense.
by ips420 September 20, 2006
Get the cap in your assmug. by Justin Russikoff April 16, 2003
Get the pop a cap in your assmug. 
The origin of bust a cap meaning to discharge a firearm has become a general threat of violence with the implication that a gun will be involved. To threaten to bust a cap in someone's ass is also not intended to be anatomically specific, as kick ass or whip your ass are not descriptive of specific actions against someone's posterior. Ass as in "your ass" "my ass" etc refers more to the whole of the physical person. Further appellations such Honky, nigga, nigger, white boy, bitch, etc. are context dependent and may not have racial or gender implications.
"I'm gonna bust a cap in yo ass" "I would never bust a cap in your ass" "Please don't bust a cap in my ass" etc
by Doc@demon September 02, 2008
Get the bust a cap in your assmug. by Fidel May 09, 2004
Get the bust a cap in your assmug. by Joe August 25, 2003
Get the pop a cap in your assmug. Something that dickheads say thinking they're saying "I'm gonna shoot you" but they're really saying "I'm going to ejaculate in your ass during anal sex" (usually homosexual)
by joveblue July 10, 2004
Get the bust a cap in your assmug.