1.5 Share definition Flag Pee is 1, and Poo is 2, so 1.5 is diarhhea. Not quite liquid, not quite solid, but everyone's favorite. I have to go 1.5 really badly. 1.5 by florentina November 5, 2003 0 0 Get merch Get the 1.5 mug. Buy Now — $32.95 See more merch