sack tap Share definition Flag A trick played on a fellow athlete where the open hand smacks the target's testicles with the knuckles in a sharp, wrist flicking motion. "Dude, I sack tapped Brandon, and now he has the whole team trying to sack tap me" sack tap by Chris M July 7, 2004 0 0 Get merch Get the sack tap mug. Buy Now — $32.95 See more merch