noun pl. gymnasiums -·si·ums or gymnasia -·sia (-ə)

1. a room or building equipped for physical training and athletic games and sports
2. in Germany and some other European countries, a secondary school for students preparing to enter a university

Etymology: L < Gr gymnasion, place for exercising < gymnazein, to train naked < gymnos, naked, stripped < IE base *nogw- > naked, L nudus