a one-piece, tightfitting, sleeved or sleeveless garment that covers, usually, only the torso: it is worn by acrobats, dancers, etc.
See leotard in American Heritage Dictionary 4
(lēˈə-tärdˌ)
noun
A snugly fitting, stretchable one-piece garment with or without sleeves that covers the torso, worn especially by dancers, gymnasts, acrobats, and those engaging in exercise workouts.