(plural major planets)
- (astronomy) Any of the 8 celestial bodies which orbit the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
- (astronomy) Any planet that is significantly larger and more massive than Earth, containing large amounts of hydrogen and helium, such as Jupiter and Neptune.
- (astronomy) Those planets that are larger than the Earth; specifically Jupiter , Saturn , Uranus , Neptune (in the Solar System)
- (astronomy) a celestial body that fits the 2006 IAU definition of planet
- dwarf planet
- minor planet