slapnashack Share definition Flag slapping the shit out of someone, because of some idiotic thing they did. When Patty threw a tantrum at the park and then called Ali immature, we had to bust a slapnashack on her ass. slapnashack by RoseDestinee June 27, 2008 0 0 Get merch Get the slapnashack mug. Buy Now — $32.95 See more merch