plan·​et | \ ˈpla-nət How to pronounce planet (audio) \

Definition of planet

1a(1) : any of the large bodies that revolve around the sun in the solar system
(2) : a similar body associated with another star
b : earth usually used with the one of the hottest places on the planet
c : any of the seven celestial bodies sun, moon, Venus, Jupiter, Mars, Mercury, and Saturn that in ancient belief have motions of their own among the fixed stars
2 : a celestial body held to influence the fate of human beings
3 : a person or thing of great importance : luminary
planet table

Other Words from planet

planetlike \ ˈpla-​nət-​ˌlīk How to pronounce planet (audio) \ adjective

Synonyms for planet


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Planet goes back to ancient Greek planēt- (literally, "wanderer"), which is derived from planasthai, a Greek verb which means "to wander." The word was originally applied to any of seven visible celestial bodies which appeared to move independently of the fixed stars—the sun, the moon, Mercury, Venus, Mars, Jupiter, and Saturn. In line with astronomical discovery and advancement, planet began to be used specifically of the rocky or gaseous bodies that orbit around the sun—a definition which excluded the moon and the sun but included the Earth and, as they were discovered, Uranus, Neptune, and Pluto. In 2006, the International Astronomical Union developed a narrower definition of planet, effectively demoting Pluto to the status of a "dwarf planet," a celestial body that is spherical and orbits the sun but is not large enough to disturb other objects from its orbit.

Examples of planet in a Sentence

our collective responsibility to conserve the planet and its natural resources for future generations
Recent Examples on the Web Every planet has an atmosphere, and each, besides our own, is unique in its particular hostility to life. Ben Taub, The New Yorker, 3 Oct. 2022 Thank you to my family; my mom for bringing me on to this planet; my father; my sister Shaheen who has helped put my talks into words; my husband Ranbin. Time, 2 Oct. 2022 This might be a familiar feeling to anyone born on this planet. Aimée Lutkin, ELLE, 1 Oct. 2022 Your time on this planet is far too valuable to be so wrapped up in what could be. Meghan Rose, Glamour, 1 Oct. 2022 There’s billions of love stories on this planet and each one is different. Brent Lang, Variety, 27 Sep. 2022 With his observations of these fast, fat, and sundry-pawed creatures, Van Leeuwenhoek became the first person to ever see a microorganism—a discovery of almost incalculable significance to human health and our understanding of life on this planet. WIRED, 27 Sep. 2022 That’s what interests me about life—a good story that attempts to wrestle with the bigger questions about our existence on this planet. Sadie Dupuis, SPIN, 26 Sep. 2022 One of those colliding with Earth could cause devastation more powerful than any nuclear weapon ever tested on this planet. Loren Grush Bloomberg News (tns), al, 26 Sep. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'planet.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of planet

14th century, in the meaning defined at sense 1a

History and Etymology for planet

Middle English planete, from Anglo-French, from Late Latin planeta, modification of Greek planēt-, planēs, literally, wanderer, from planasthai to wander — more at floor

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The first known use of planet was in the 14th century

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Dictionary Entries Near planet

plane symmetry


plane table

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Last Updated

5 Oct 2022

Cite this Entry

“Planet.” Dictionary, Merriam-Webster, Accessed 7 Oct. 2022.

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More Definitions for planet


plan·​et | \ ˈpla-nət How to pronounce planet (audio) \

Kids Definition of planet

: any large heavenly body that orbits a star (as the sun)

More from Merriam-Webster on planet

Nglish: Translation of planet for Spanish Speakers

Britannica English: Translation of planet for Arabic Speakers Encyclopedia article about planet


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