Full knuckle Share definition Flag When you stick your hand in someone's asshole, made famous by skiier Jonny Moseley ADDISON: DUDE MY GIRLFRIEND WANTS ME TO FULL KNUCKLE HERERIC: DO IT! Full knuckle by Joesretrogames May 4, 2018 0 0 Get merch Get the Full knuckle mug. Buy Now — $32.95 See more merch