YSIW Share definition Flag Your Shit Is Weak - Usually when someone is being a complete idiot, pansy, or douchebag. Friend won't go with you somewhere cuz they are tired. You say "YSIW". YSIW by Schuy December 20, 2008 0 0 Get merch Get the YSIW mug. Buy Now — $32.95 See more merch
