Young college female, often times a member of a sorority, who spends an excessive amount of time having sex with brothers of a
fraternity.
the term derives from
fraternity + mattress, because the slut spends so much time under brothers that she might as well be their
bed.
"Bro, you see that frattress over there? Yeah, the one on
top of the table. I'm gonna do work and put her to use tonight."
"So, I was banging this frattress the other
night, and after we got done she told me not to tell any of my brothers. You know she's just gonna tell those other sorostitutes how awful of a
guy I am."