planet meaning
EN
[ˈplanɪt] [ˈplænət] [-ænɪt] 
US WPlanet
- A planet (from Ancient Greek ἀστήρ πλανήτης, astēr planētēs, or πλάνης ἀστήρ, plánēs astēr, meaning "wandering star") is an astronomical object orbiting a star or stellar remnant that
- is massive enough to be rounded by its own gravity,
- is not massive enough to cause thermonuclear fusion, and
- has cleared its neighbouring region of planetesimals.
- The term planet is ancient, with ties to history, science, mythology, and religion. Several planets in the Solar System can be seen with the naked eye. These were regarded by many early cultures as divine, or as emissaries of deities.
- NounPLplanets
- (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.
- (astronomy) A body which orbits the Sun directly and is massive enough to be in hydrostatic equilibrium (effectively meaning a spheroid) and to dominate its orbit; specifically, the eight major bodies of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. (Pluto was considered a planet until 2006 and has now been reclassified as a dwarf planet.).
- A large body which directly orbits any star (or star cluster) but which has not attained nuclear fusion.
- In phrases such as the planet, this planet, sometimes refers to the Earth.
- (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.
- More Examples
- Used in the Middle of Sentence
- The normal condition of every species on this planet is not progress but stationariness.
- Microlensed double-image quasars have sent a consistent message that the baryonic dark matter consists of a dark population of free-roaming planet mass objects.
- A state-of-the-art ‘Mars yard’ is now ready to put the ExoMars rover through its paces before the vehicle is launched to the Red Planet in 2018.[1]
- Used in the Ending of Sentence
- To explain these observations a model was developed involving stimulated radiative molecular association (SRMA) reactions among photons and atoms in the protosatellite disks of the planets.
- Arab League is the most useless organization on the planet.
- I was terribly scared by Idi Amin's animosity that iron handedly ravaged the earth as if he was from a different planet.
- Used in the Middle of Sentence
Definition of planet in English Dictionary
- Part-of-Speech Hierarchy
- Nouns
- Countable nouns
- Countable nouns
- Nouns
Source: Wiktionary
Grammatically, this word "planet" is a noun, more specifically, a countable noun.