Tragically and almost perpetually unattached people that hang out in the lobbies or front steps of college or boarding school dorms waiting for a breakup or someone desparate, drunk, or pathetic, to fall dead (or single) and they swoop down to try to score on the remnants. these people know they are a rebound date, that is what they live for. Either sex can be a dorm buzzard. Dorm Buzzards are generally the same people that were dateless throughout high school and are usually unattractive in some way.
I'd like to go out, but at this short notice all I could get is a Dorm Buzzard. I'd rather do homework than that.