planetarium

noun

plan·​e·​tar·​i·​um ˌpla-nə-ˈter-ē-əm How to pronounce planetarium (audio)
plural planetariums or planetaria ˌpla-nə-ˈter-ē-ə How to pronounce planetarium (audio)
1
: a model or representation of the solar system
2
a
: an optical device for projecting various celestial images and effects
b
: a building or room housing such a projector

Examples of planetarium in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Bridgers will not be in attendance for any of the shows at the planetarium. — Joseph Hernandez august 6, Kansas City Star, 6 Aug. 2026 And packing no GoTo computer requires at least a rudimentary knowledge of the night sky and a star atlas or planetarium software. — Damian Peach, Space.com, 4 Aug. 2026 There’s also an adventure center with interactive exhibits, a garden filled with plants native to Hawaii, and a planetarium. — Sharael Kolberg, Travel + Leisure, 26 June 2026 Plus, the Bishop Museum of Science and Nature, a Smithsonian affiliate, features a planetarium and a manatee rehabilitation habitat. — Kelsey Glennon, Southern Living, 23 June 2026 See All Example Sentences for planetarium

Word History

First Known Use

1860, in the meaning defined at sense 1

Time Traveler
The first known use of planetarium was in 1860

Rhymes for planetarium

See All Rhymes for planetarium

Browse Nearby Words

planetarily
planetarium
planetary
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Cite this Entry

“Planetarium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/planetarium. Accessed 13 Aug. 2026.

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Kids Definition

planetarium

noun
plan·​e·​tar·​i·​um ˌplan-ə-ˈter-ē-əm How to pronounce planetarium (audio)
plural planetariums or planetaria -ē-ə How to pronounce planetarium (audio)
1
: a device that projects images of heavenly bodies on a ceiling shaped like a dome
2
: a building or room housing a planetarium

More from Merriam-Webster on planetarium

Nglish: Translation of planetarium for Spanish Speakers

Britannica.com: Encyclopedia article about planetarium

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