look up any word, like cunt:
1.Past tense of "flatbacking." To have slept (ie sexed) your way through something.

2. To have prostituted your way through something, either by trading for sex or by selling sex for money in order to pay.
"She won't be the first co-ed to have flatbacked her way through college." Ice-T (Law & Order: SVU)
by Country Girl Big City June 20, 2012