Getting fired from your job. Australians use this phrase a lot. Probably from the pioneer days when the boss would throw a bag at the farmhand/miner/builder/labourer's head, tell him to pack his stuff and get lost.
"Bloody hell, the boss gave me the sack!"
"Are you going to get the sack for skipping work yesterday?"
"Are you going to get the sack for skipping work yesterday?"
by oneof20million June 10, 2009
Get the get the sackmug. by TTENNEB EKIM September 27, 2005
Get the tacky sackmug. A prank that is pulled usually in high school by taking someone's back pack, taking everything out, turning the backpack inside out and putting the stuff back in.
by YarmouthClippers June 13, 2009
Get the Ninja Sackmug. Stuffing your balls inside a vaginal cavity like packing a pipe with your thumb while jerking off onto declared body part such as stomach or back (if flexible). Also called "sack n whack".
by deadly muffin November 16, 2010
Get the Sack and Whackmug. 
A term used to describe the virtual balls of people who trash talk in an online thread because they know you can't throttle them through the screen.
by TheGhostrider420 August 7, 2014
Get the net sackmug. by Stan "the sweet stink" D... June 20, 2011
Get the Skunk sackmug.