Learn how to say Planetarium correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word planetarium:
noun (plural planetariums or planetaria /-rɪə/)
1a domed building in which images of stars, planets, and constellations are projected for public entertainment or education.
a device used to project images of stars, planets, and constellations.
2another term for orrery.
mid 18th century: modern Latin, from Latin planetarius ‘relating to the planets’