Muffslice Share definition Flag An awesome insult used to describe an idiot/prick/bawbag/arsehole, basically anybody you don't like. Can be used in any situation. Don't be such a muffslice! What a muffslice he is! Your mum is a muffslice! Muffslice by big gav teh tank January 15, 2009 0 0 Get merch Get the Muffslice mug. Buy Now — $32.95 See more merch