Ass jelly Share definition Flag Of, or related to diarrhea; Found in between the butt cheeks of a person dealing with diarrhea. Caused by lack of wiping. I've had the runs all week, and I think I've got mad ass jelly. Ass jelly by Johan McTrumpet November 16, 2003 0 0 Get merch Get the Ass jelly mug. Buy Now — $32.95 See more merch