Humper Bumper Share definition Flag 1. Nown - Butt 2. Nown - Ass 3. Nown - Backside 4. Nown - Booty Check out the humper bumper on that chick. That girl has a thick humper bumper. Humper Bumper by wile September 8, 2013 0 0 Get merch Get the Humper Bumper mug. Buy Now — $32.95 See more merch