pebble mud Share definition Flag The bit of poo that hangs on when you accidentally squeeze it off too soon. I squeezed it off to soon, and I had to use a whole roll of toilet paper to get rid of the pebble mud. pebble mud by ravenhiss September 15, 2003 0 0 Get merch Get the pebble mud mug. Buy Now — $32.95 See more merch