gravy baby Share definition Flag A messy, watery, loose stool that is excreted with childbirth-like pain and has a color and consistency not unlike turkey gravy. "Don't use stall #3 - someone left behind a gravy baby and didn't flush." gravy baby by Joe Pseudonym November 28, 2012 0 0 Get merch Get the gravy baby mug. Buy Now — $32.95 See more merch