Fat Tarts Share definition Flag A fat, but flat chested girl who creates the illusion of having tits by pulling the fat from her back, and then stuffing it into a push-up bra. Monte: Check out her tits! Rick: Naw man, those are fat tarts. Monte: Snarf. Rick: Ruh Roh. Fat Tarts by ChellChell September 8, 2010 Get the Fat Tarts mug.