A female, usually possessing saggy tits, a flat ass, and an ugly face, and feels she has something to prove by fucking anything with two legs or batteries. She will try to sleep with your boyfriend with no success, and when she enters a room, it clears out most efficiently, due to the smell of rotting fish. Desperate, horny guys are her prey of choice, but she occasionally with settle for another slut bag to ensure that she's still the topic of discussion by the people she percieves to be her friends, but who in reality, like her as much as they'd enjoy a bout of gonnoreah. Guys who have slept with her won't own up to it, unless they're making fun of her, and were really tanked at the time of social suicide. Her best attributes can only be seen when beer goggles are an understatement. Beware to all, for the slut bag is everywhere, and the only warning of her approach is the stench of STD's and other vial smelling things, such as the trap that lays between her legs. Ye be 'fore warned.

a really really dirty slut!

an affectionate term for a slutty friend

one who is of the whoring nature, and will indefinitely fuck, suck or sha-bang anything of walking ability

A bag of slut
-or-
A bag, possibly a burlap sack, filled with sluts

a girl who is very dirty and would sleep with anything with two legs

A slut to the Nth degree. A slut that is so slutty, she is considered a slut bag - a veritable cum dumpster.