[gym.na.si.um] n, pl -na.si.ums or -na.sia [L, exercise ground, school, fr. Gk gymnasion, fr. gymnazein to exercise naked, fr. gymnos naked--more at naked] (1598) 1 a: a large room used for various indoor sports (as basketball or boxing) and usu. equipped with gymnastic apparatus b: a building (as on a college campus) containing space and equipment for various indoor sports activities and usu. including spectator accommodations, locker and shower rooms, offices, classrooms, and a swimming pool
2. [G, fr. L, school]: a European secondary school that prepares students for the university