- an apparatus or model representing the planetary system.
- a device that produces a representation of the heavens by the use of a number of moving projectors.
- the building or room in which such a device is housed.
Origin of planetarium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for planetarium
The planets are visible during the day in the planetarium as well as night.
Ingulfus mentions at the same time a nadir, as he calls it, or planetarium, executed in various metals.
In the school-room there was a planetarium, very neatly finished, set in motion by clock-work.Travels Through North America, v. 1-2
Berhard Saxe-Weimar Eisenach
The dome was lighted to represent a clear night, and, incidentally, all nights are clear in a planetarium.
- an instrument for simulating the apparent motions of the sun, moon, and planets against a background of stars by projecting images of these bodies onto the inside of a domed ceiling
- a building in which such an instrument is housed
- a model of the solar system, sometimes mechanized to show the relative motions of the planets
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for planetarium
1734, "orrery," Modern Latin, from Late Latin planeta (see planet) + Latin -arium "a place for." Sense of "device for projecting the night sky onto the interior of a dome" is attested from 1929.
Online Etymology Dictionary, © 2010 Douglas Harper