planet
UK /ˈplænɪt/ · US /ˈplænət/ noun
Forms planets
- noun (now historical or astrology) Each of the seven major bodies which move relative to the fixed stars in the night sky—the Moon, Mercury, Venus, the Sun, Mars, Jupiter and Saturn.
- noun (astronomy, historical) Any body that orbits the Sun, including the asteroids (as minor planets) and sometimes the moons of those bodies (as satellite planets)
- noun (astronomy, current) A body which is massive enough to be in hydrostatic equilibrium (generally resulting in being an ellipsoid) but not enough to attain nuclear fusion and, in IAU usage, which directly orbits a star (or multiple star) and dominates the region of its orbit; specifically, in the case of the Solar system, the eight major bodies of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
- noun construed with the or this: The Earth.
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Antonyms
Etymology
From Middle English planete, from Old French planete, from Latin planeta, planetes, from Ancient Greek πλανήτης (planḗtēs, “wanderer”) (itself an ellipsis of ἀστέρες πλανῆται (astéres planêtai, “wandering stars”)), from Ancient Greek πλανάω (planáō, “wander about, stray”), of unknown origin. Cognate with Latin pālor (“wander about, stray”), Old Norse flana (“to rush about”), and Norwegian flanta (“to wander about”). More at flaunt. So called because they have apparent motion, unlike the "fixed" stars. Originally including also the moon and sun but not the Earth; modern scientific sense of "world that orbits a star" is from 1630s in English. The Greek word is an enlarged form of πλάνης (plánēs, “who wanders around, wanderer”), also "wandering star, planet", in medicine "unstable temperature." Displaced native Old English tungol.
Webster’s 1913
- noun A celestial body which revolves about the sun in an orbit of a moderate degree of eccentricity. It is distinguished from a comet by the absence of a coma, and by having a less eccentric orbit. See Solar system.
- noun A star, as influencing the fate of a men. There's some ill planet reigns. Shak.
Sources: Wiktionary · WordNet 3.0 · Webster’s 1913 — from the Wiktionary entry “planet”, CC BY-SA 4.0. Details