1. a celestial body moving in an elliptical orbit round a star.
▪ the earth: "no generation has the right to pollute the planet"
▪ a celestial body distinguished from the fixed stars by having an apparent motion of its own (including the moon and sun), especially with reference to its supposed influence on people and events:"the planets are presently influencing you in a positive way"
Word OriginMiddle English: from Old French planete, from late Latin planeta, planetes, from Greek planētēs ‘wanderer, planet’, from planan ‘wander’.