planetarium

noun

plan·​e·​tar·​i·​um ˌpla-nə-ˈter-ē-əm 

plural planetariums or planetaria ˌpla-nə-ˈter-ē-ə 

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

What about being immersed in a 360-degree planetarium? —Meredith G. White, The Arizona Republic, 22 June 2024

Sally’s Night at the Air and Space Museum honors Sally Ride with planetarium shows, trivia challenges and hands-on science experiments until 11 p.m. —Chris Kelly, Washington Post, 21 June 2024

Your sleepover includes meals, hands-on activities, exclusive after-hours time in the exhibits, planetarium shows and telescope viewing amidst the backdrop of the redwood forest. —Brittany Delay, The Mercury News, 13 June 2024

Multiple showtimes between 11 a.m.-2 p.m., April 20, planetarium. —Claire Reid, Journal Sentinel, 15 Apr. 2024

Word History

First Known Use

1860, in the meaning defined at sense 1

Kids Definition

planetarium

noun

plan·​e·​tar·​i·​um ˌplan-ə-ˈter-ē-əm 

plural planetariums or planetaria -ē-ə 

1

: a device that projects images of heavenly bodies on a ceiling shaped like a dome

2

: a building or room housing a planetarium