whoopi slap Share definition Flag When someone fills their butthole full of air and then they slap somebody with it and let out a poo. My boyfriend decided to try a new move on me called a whoopi slap. It was so gross. whoopi slap by Benny G East January 15, 2011 0 0 Get merch Get the whoopi slap mug. Buy Now — $32.95 See more merch