Someone who has a flatback as a result of laying on their back too much. Who are of a promiscious nature. Or simply, a female who is a sloppy, loose, trollup.
"man, that Deanna, she is such a flat back, I have seen her with 3 different guys this week!"
or
"Wow, why is he dating that flatback whore?"
or
"Wow, why is he dating that flatback whore?"
by Elphaba. W. Witch August 5, 2008

by Fat rabbit June 28, 2019

by Phyllis Biggun July 16, 2008

by Jack Metcoff August 12, 2025

Some lady who thinks its ok to make her way on her life path while being flat on her back, giving up what's between her legs, in order to get there.
I can't believe how that chick sits back and gets paid, is given a car, and she is just a foul flatbacker!
by AshKraft August 10, 2021

by Chodemuncher September 8, 2023

by Major.horsecock December 22, 2023
