Pronunciation: (plan"i-târ'ē-um), [key]
—pl. -tar•i•ums, -tar•i•aPronunciation: (-târ'ē-u). [key]
1. an apparatus or model representing the planetary system.
2. a device that produces a representation of the heavens by the use of a number of moving projectors.
3. the building or room in which such a device is housed.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.