flatbacker

plural flatbackers

1. slangA female prostitute who services a large number of customers.

   If we had straight flatbackers, as we called them, they turned a date for twenty or twenty-five dollars. Nobody was allowed to rob them because they'd become regular customers.

   2014, John Turnipseed, Cecil Murphey, Bloodline

   2 more examples

   Good flatbackers always fare well, which accounts for their swelling ranks. They work the offices along Madison and Lex like a Schrafft's super-hospitality wagon. Score the flustered john in the elevator, simple!

   1971, New York Magazine, volume 4, number 30, page 26

   He had four girls in this stable and worked them as “flatbackers”—they would take anyone on, one after another, fifteen, twenty tricks a night, and it didn't matter if the girls were sick, menstruating, whatever: they had to work […]

   2016, Tom Philbin, Precinct: Siberia