planet

noun plan·et \ˈpla-nət\

: a large, round object in space (such as the Earth) that travels around a star (such as the sun)

the planet : the planet Earth

—used in informal phrases to say that someone is not aware of what is really happening or has ideas that are not realistic or practical

Full Definition of PLANET

a : 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

b (1) : any of the large bodies that revolve around the sun in the solar system (2) : a similar body associated with another star

c : earth —usually used with the

: a celestial body held to influence the fate of human beings

: a person or thing of great importance : luminary

planet table

See planet defined for English-language learners

See planet defined for kids

Origin of 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

First Known Use: 13th century

Related to PLANET

Synonyms: globe, earth, world

Rhymes with PLANET

gannet, granite

PLANET Defined for Kids

planet

noun plan·et \ˈpla-nət\

Definition of PLANET for Kids

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

Word History of PLANET

Most stars seem to stay in fixed positions night after night. There are certain heavenly bodies, the planets, that look very much like stars but are not. They seem to wander about among the fixed stars. The ancient Greeks gave them the name planētes, meaning “wanderers.” The English word planet comes from this Greek word.