To 'Crotch Out' or 'Crotching Out' is when a female sits or slouches in an unladylike fashion (often for comfort reasons), with her legs akimbo and her crotch or vagina facing outwards.
A male who lowers their drawers and proceeds to rotate his hips in order to project & swing his member in a motion that resembles that of a ferris wheel or helicopter. This is often done from an open window on public transportation or a trolley.