Top Definition
The part of a man no one should ever have to see. More specifically, the back of a man's scrotum.
Dude, when I was in the locker room today I totally saw some old guy's wrinkly backsack.
by JohnC7 February 16, 2008
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
to view testicles from behind usually caught on camera upon showing your friends your arse and leaning a little too far forward
On reviweing holiday pics:
"that was when you got your arse out, whats that dark patch between your legs?"
by Dr Diddy January 21, 2009
an unfourtunate birth defect where instead of having a nutsack next to your tallywacker, you have one on your back
I fell off my bike and my back sack exploded
by ice dragon April 04, 2009
Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.