The term yam sack originated from the bag that farm workers would hang from their belt in front of them while harvesting yams. Now the term yam sack is generally used in reference to the testicles or bean bag. Also see yam bag.
Dumbass...punch yourself in the yam sack for saying that.
by Matt Park February 06, 2005
Another name for scrotum...where a man's 'yams' are kept.
Ooh..that's gotta hurt! Swift kick to the yamsack!
by Kickstart January 21, 2005