3lbfb Share definition Flag Three Pound Food Baby. A large bowel movement. You can use any number you want to denote the size of the poo, but the number three has a ring to it. "Three el bee eff bee" I've got a 3lbfb on the way. 3lbfb by Devoknox December 7, 2006 0 0 Get merch Get the 3lbfb mug. Buy Now — $32.95 See more merch
