| planet | |
| 1. n. (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. | |
| 2. n. (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 | |
| 3. n. A large body which directly orbits any star (or star cluster) but which has not attained nuclear fusion. | |
| 4. n. In phrases such as the planet, this planet, sometimes refers to the Earth. | |
