Sackjaw Share definition Flag when a female (or a male) gives so much head they get a bruise on their chin from the testicles smacking vigerously upon it. "whoA did you see brendas sackjaw?" Sackjaw by JounA December 31, 2004 0 0 Get merch Get the Sackjaw mug. Buy Now — $32.95 See more merch