1. An institution where people pay for the privilege of torturing themselves through bodily exertion in the name of physical fitness. Torture implements in most gymnasiums include freeweights, excercise bicycles, circuit training machines, rowers, etc. Attendees seem to enjoy the fact that not since the Spanish Inquisition has there been such a wide selection of torture implements available, as the success of a gymnasium is correlated partly to the amount of equipment it has to offer.
2. A moneymaking enterprise that offers a cheap, long-term membership deal right around New Year's to entice January Joiners bent on fulfilling their New Year's resolutions. The amount of revenue these fickle individuals generate for the fitness industry is unfathomable.