Cap a mf Share definition Flag (Verb): Meaning to kill a person, specifically (but not always) to kill a mother fucker with a gun. Antwon: Yo Confandre’s bitch ass snitched on you! DeShawn: Look like I’m a cap a mf. Cap a mf by thevalleyboy July 11, 2019 0 0 Get merch Get the Cap a mf mug. Buy Now — $32.95 See more merch