egg butt Share definition Flag A particularly awful smelling fart from deep within the bowels. It has the distinct sulfur odor usually associated with rotten eggs. Stan: Dude, did you just shit your pants?Eric: Mmmm, no. It was just egg butt. egg butt by moraleboatanchor August 15, 2012 0 0 Get merch Get the egg butt mug. Buy Now — $32.95 See more merch