1 definition by J'Nathan Bo'Jingles

Back Sack is the backside of ones scrotum.
A: Yo dog, I can't believe you just ball-tapped me from behind, you got all back-sack.
B: Ew, check out that old guy's back-sack hanging out of his pants.
C: Check out Katz's shaved back-sack.
D: Mom, Jacob put his back-sack on my face.
by J'Nathan Bo'Jingles May 25, 2008
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