planet

1. (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.Examples: "Be they not dreames of humane vanity,[…]to make of our knowne earth a bright shining planet [translating astre]?"; "The moon[…]began to rise from her bed, where she had slumbered away the day, in order to sit up all night. Jones had not travelled far before he paid his compliments to that beautiful planet, and, turning to his companion, asked him if he had ever beheld so delicious an evening?"; "Another of Boehme's followers, the Welshman Morgan Llwyd, also believed that the seven planets could be found within man."historical

2. (astronomy, historical) Any body that orbits the Sun, including the asteroids (as minor planets) and sometimes the moons of those bodies (as satellite planets)Examples: "A Discovrse concerning a New Planet. Tending to prove, That 'tis probable our Earth is one of the Planets"Synonyms: wandering star, wanderstarhistorical

3. (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.Examples: "Their decision will force a rewrite of science textbooks because the solar system is now a place with eight planets and three newly defined "dwarf planets"—a new category of object that includes Pluto."; "The closest planet takes just over nine Earth days to complete an orbit around the star, and the most distant takes about 55 days. All of the planets have quicker revolutions around their star than Mercury, which takes 88 days to complete one lap around the sun."Synonyms: world