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1.
wearing two pair of tighty-whitey underpants in an attempt to warm the balls
before going ice fishing, Adrian made sure to sack pack so as to avoid shrinkage.
by the vins April 01, 2006
 
2.
A draw string bag that is often used by athletes. it is one of the few types of bags that a guy may use for non-academic material and not be considered gay. it is by no means to be confused with a murse.
"did you see the guy with sackpack I bet he plays a lot of sports."
by dacrazy1 November 08, 2011
 
3.
A bag held together by string that is typically worn on the backs of athletes for the holding of non-academic material such as cleats, frisbees and lipstick. It can sometimes and understandably be confused with a murse. The owner of the sackpack can be mistaken for a gay man when in reality, he just plays a bunch of sports.
Person 1: Did you see that guy with the sackpack? I bet he plays a lot of sports.
Person 2: Yeah, I bet he's the team rump ranger.
Person 1: Word.
by your girlfriend wins November 16, 2011