outer planet

[ou-ter plan-it]

noun

Astronomy.

1. any of the planets in our solar system whose orbits lie beyond the asteroid belt, namely, Jupiter, Saturn, Uranus, and Neptune: before its reclassification as a dwarf planet in 2006, Pluto was included among the outer planets.

outer planet

noun

1. any of the planets Jupiter, Saturn, Uranus, Neptune, and (formerly) Pluto, whose orbit lies outside the asteroid belt

outer planet

1. Any of the four planets Jupiter, Saturn, Uranus, and Neptune, whose orbits lie outside that of Mars. The outer planets are large gas giants.

2. Compare inner planet See also superior planet

Word History and Origins

Origin of outer planet¹

First recorded in 1940–45