Shit-yack Share definition Flag To wake up so hungover you can't decide if you need to shit or yack, that it's usually happens simultaneously. "Man, I don't know If I have to shit or yack. I just shit-yacked." Shit-yack by Violently hungover November 30, 2013 0 0 Get merch Get the Shit-yack mug. Buy Now — $32.95 See more merch