mostly used by women to refer to a
casual sexual partner they can call up for a booty
call any time, regardless of her relationship status.
It's no-strings, no-emotions, hardcore sex-only.
Men often use the term fuck buddy for the same thing.
A more gender neutral term might be
friends with benefits
Karen: "Damn, another lousy boyfriend
history, I think I need to call my recyclable,
Rico, to get myself grounded before hunting up a new boyfriend.