To cum in a girl's ass. Originally a meteorological term, meaning in a supercell thunderstorm, an area of dry air that wraps around the back end of a mesocyclone.
Guy 1: Boy, I sure like that girl Brandi! I'd like to give her a rear flank downdraft.

Guy 2: Ya me too man.
by 212crank530 January 1, 2011
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