Wordnet 3.0
NOUN (3)
1.
a building housing an instrument for projecting the positions of the planets onto a domed ceiling;
2.
an optical device for projecting images of celestial bodies and other astronomical phenomena onto the inner surface of a hemispherical dome;
3.
an apparatus or model for representing the solar systems;
The Collaborative International Dictionary of English v.0.48:
Planetarium \Plan`e*ta"ri*um\, n. [NL.: cf. F. plan['e]taire.
See Planetary.]
An orrery. See Orrery.
[1913 Webster]
WordNet (r) 3.0 (2006):
planetarium
n 1: a building housing an instrument for projecting the
positions of the planets onto a domed ceiling
2: an optical device for projecting images of celestial bodies
and other astronomical phenomena onto the inner surface of a
hemispherical dome
3: an apparatus or model for representing the solar systems
Moby Thesaurus II by Grady Ward, 1.0:
22 Moby Thesaurus words for "planetarium":
Cassegrainian telescope, Newtonian telescope, OAO, OSO,
astronomical observatory, astronomical telescope, coelostat,
coronagraph, coronograph, heliostat, observatory, orrery,
radar telescope, radio observatory, radio telescope, reflector,
refractor, spectrograph, spectroheliograph, spectrohelioscope,
spectroscope, telescope