A women or man who gets drunk, has sex with multiple partners and then passes out in the gutter like the fucking slut that they are. Usually applied to trashy as hell whores but can also apply to anyone who gets heavily drunk and heavily promiscuous.
Brianna "Look at the gutter slut, she looks so nasty down there in that gutter"
Kody "That is just Jenny she is such a whore it doesn't really matter"
Nikki "OMG a gutter slut, they don't look trashy"
Brianna "It's okay, they are probably just a one time gutter slut"