An unpleasant name for someone. Sack = Scrotum, nut = testicle, sacknut = scrotumtesticle.
"You are a sacknut", "Oi! Sacknut" or "Hello sacknut".
by Chubbs McGroin November 20, 2006
Oh shit man, that almost hit me in the sacknuts
by That Druid Man June 24, 2011