fat slab Share definition Flag (N) A fat ass, A donk, A Booty, Junk in the trunk, cake. Jerad: Gurl you got a fat slab!Amber: Why you lookin at my ass?! Pervert! fat slab by Shimmerlake May 11, 2015 0 0 Get merch Get the fat slab mug. Buy Now — $32.95 See more merch