n., gym machines for leg exercises. Known in the fitness industry formally as "hip abductor" and "hip adductor," the user is seated, either with pads between the knees or knees beween the pads. Legs are spread as wide as possible and then brought together while user encounters weight resistance from the machine. Frequented almost exclusively by women club members who appear to find the exercise rewarding, presumably because of superior lower-body strength.
"Every time I come to the gym, there's Ms. Thunderthighs, flapping away at the SnatchMaster."