nounpl. -·iums or -·ia
- a complex revolving projector used to simulate the past, present, or future motions or positions of the sun, moon, planets, and stars on the inside of a large dome
- the room or building in which this is contained
Origin of planetariumModern Latin from Late Latin planeta, planet + Classical Latin (sol)arium, solarium
nounpl. plan·e·tar·i·ums, or plan·e·tar·i·a
- An apparatus or model representing the solar system.
- a. An optical device for projecting images of celestial bodies and other astronomical phenomena onto the inner surface of a hemispherical dome.b. A building or room containing a planetarium, with seats for an audience.
(plural planetariums or planetaria)
From New Latin, formed from planet +"Ž -arium.