poo out Share definition Flag 'to poo out' - to back out of a situation, to let someone down 'are you still coming out on Friday Eleanor?' 'sorry I can't I'm skint' 'noooo don't poo out' poo out by jessicatmiaow April 6, 2009 0 0 Get merch Get the poo out mug. Buy Now — $32.95 See more merch