A derogotory term for someone you hate, use it, love it. Generally speaking, these people fucking suck.
Dude, that guy is the biggest fucksack I have ever met...rot in hell, FUCKSACK!
by bonedoggy March 22, 2004
Someone that a person keeps on the side. Sole purpose to fuck without commitments.
The bar closes and all the hotties are gone, that's okay I gotta fuck sack I can visit.
by mdaddy September 14, 2006
1. A person with whom you have relations and then toss aside like an empty paper sack.
1. Ashley's nice and all, but I don't see him as anything but a single-serving fucksack.
by Nick Necrosis November 25, 2009