look up any word, like b4nny:
The loose skin on the cheeks of the buttocks.
I'm gonna rape you in the buttsack!
by JimmyK1230 August 20, 2011
A puss filled pouch of skin found in anus or on the buttocks of grown men, used by rodents (usually mice or rats) for nesting, burrowing, gathering, ect.
I set a mouse trap in my cousin's buttsack in an attempt to catch dinner.
by Dr. Gertrude February 28, 2011
A word commonly used by teenagers , referring to the back side of your ball sack.
Ouch, dude, you hit my butt sack.
by Wekranian July 02, 2009
A surgical procedure that attaches ones saggy or taut scrotum to their rectum or sometimes the sphincter.

Ayo tracy! Billy just got himself a brand new buttsack and it is looking nice!
by booty holes January 11, 2009
the male version of the g-spot
Trav-"Did you hookup with smashley last night"
Jerry-"Yeah, she found my buttsack and i immediately came in her face"
by KingOfTheBROcean July 18, 2010
An older woman's saggy butt that hangs down like a sack
Guy 1: Hey isnt that your grandma?
Guy 2: No way man, she's got a butt sack!
by joe peterson August 15, 2006
When a guy who is naked bends over and you can see his sack hanging between his legs, beneath his butt.
My boyfriend bent over after his shower and I got a full view of his butt sack.
by stud masterson April 11, 2008