Definition of planet
1a : 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 starsb (1) : any of the large bodies that revolve around the sun in the solar system (2) : a similar body associated with another starc : earth —usually used with the
2 : a celestial body held to influence the fate of human beings
3 : a person or thing of great importance : luminary
planetlikeplay \ˈpla-nət-ˌlīk\ adjective
planet was our Word of the Day on 06/28/2012. Hear the podcast!
Examples of planet in a Sentence
our collective responsibility to conserve the planet and its natural resources for future generations
Recent Examples of planet from the Web
Since Mr. McCain ran for president on climate credentials that were stronger than his opponent Barack Obama’s, the scientific evidence linking greenhouse gases from fossil fuels to the dangerous warming of the planet has grown stronger.
Is enough do, the planet will end up as something out of a science-fiction nightmare.
The potential consequences of Washington abandoning the climate pact are grave not only for the planet but also for the U.S., its economic competitiveness, technological innovation, and leadership of the world in the 21st century.
In the Gift Theatre's latest, a quarantined soldier and teenage girl face their pasts on a spacecraft sent to colonize a new planet.
The large, gaseous planet — appearing to float through the constellation Virgo now — rises in the midafternoon throughout June and hits due south soon after nightfall early in the month.
The look is lush, with colorful, uniquely shaped plants of the far-flung planet.
Among the 650 entries from 18 different countries and 15 states were shots of some of the planet’s most awesome inhabitants, from baby flying fish flapping in the inky black to a school of eerie batfish.
Skimming just 5,000 kilometers above the cloud tops, Juno flies closer to Jupiter than any spacecraft has before (not counting the time the Galileo orbiter intentionally crashed into the planet to end that mission in September 2003).
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.
Did You Know?
Planet goes back to ancient Greek planēt- (literally, "wanderer"), which is derived from "planasthai," a Greek verb which means "to wander." The name "planet" 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 the 17th century, "planet" began to be used specifically of the rocky or gaseous bodies that orbit around the sun - a definition which excluded the moon and, obviously, 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.
Origin and Etymology 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: 14th century
PLANET Defined for Kids
Definition of planet for Students
: any large heavenly body that orbits a star (as the sun)
History for 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.
Learn More about planet
Seen and Heard
What made you want to look up planet? Please tell us where you read or heard it (including the quote, if possible).