diarrhilarious Share definition Flag A joke or situation so hilariously funny that it makes you laugh so hard that you shit in your pants. Oh man, you better wear Depends if you go see Borat. It's diarrhilarious. diarrhilarious by figgarroo77 November 17, 2009 0 0 Get merch Get the diarrhilarious mug. Buy Now — $32.95 See more merch