High school senior boys without dates for prom that "creep" around the freshman section at school around April, all in hopes of finding a decent looking freshman girl to ask to prom, in order to avoid embarrassment by showing up dateless.
Guy 1: "Dude, you got a date for prom?"
Guy 2: "No. But I think I'll ask a freshman. They're desperate."
Guy 1: "Yeah man, good idea. So true by the way."
Guy 3: "Psh, Senior Creepers. Good luck with that."