say it: jim-NAY-zee-uhm
gymnasium is a noun meaning "a school for students intermediate between elementary school and college; usually grades 9 to 12". It carries 2 recorded senses.
a school for students intermediate between elementary school and college; usually grades 9 to 12
athletic facility equipped for sports or physical training
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for gymnasium come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.