major planet

Noun

 * 1)  Any of the 8 celestial bodies which orbit the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune (a celestial body that fits the 2006 IAU definition of planet).
 * 2)  Any planet that is significantly larger and more massive than Earth, containing large amounts of hydrogen and helium, such as Jupiter and Neptune.

Antonyms

 * smaller than Earth (in the Solar System)
 * a planet that does not fit the 2006 IAU definition of planet (i.e. Pluto)