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
Idiom of the Day
put (someone) up to (something)
to persuade or cause someone to do something
The young boy's friend put him up to cheat on the examination.