(noun) 1. A cum dumpster with benefits.
2. A girl so desperate for a boyfriend that she does girlfriendly things for every guy in hopes that one will date her. One must be suffienctly unattractive in order to maintain the "fake girlfriend" status lest someone would actually want to date her.
Guy A: "Dude, she made me dinner and let me fuck her raw dog last night"
Guy B: "She made me waffles today and sucked my dick."
Guy C: "Communal girlfriend is coming over tonight when my girlfriend is away. Hopefully I can get some cookies and anal sex from our communal girlfriend!"