Definition of planetarium noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
Define planetarium. planetarium synonyms, planetarium pronunciation, planetarium translation, English dictionary definition of planetarium. n. pl. plan·e·tar·i·ums or plan·e·tar·i·a 1. An apparatus or model representing the solar system. 2. a. An