clumping Share definition Flag to have sex with a woman while wearing a clown costume. dervies from the combination of the words clown and humping. "Dude did you have sex with my sister?" "I clumped her ass, son" clumping by NiMo March 1, 2005 0 0 Get merch Get the clumping mug. Buy Now — $32.95 See more merch