outer planet
noun Astronomy.
any of the four planets with orbits outside the orbit of Mars, namely, the planets Jupiter, Saturn, Uranus, and Neptune.
Compare
inner planet.
Origin of outer planet
First recorded in 1940–45
Words nearby outer planet
outer barrister,
outer ear,
outer garments,
outer hebrides,
outer mongolia,
outer planet,
outer product,
outer space,
outercoat,
outercourse,
outermost
Example sentences from the Web for outer planet
I've heard of it, but as this is my first outer-planet voyage, I know nothing about it.
The Sargasso of Space |Edmond Hamilton
British Dictionary definitions for outer planet
outer planet
noun
any of the planets Jupiter, Saturn, Uranus, Neptune, and (formerly) Pluto, whose orbit lies outside the asteroid belt
Scientific definitions for outer planet
outer planet
Any of the four planets Jupiter, Saturn, Uranus, and Neptune, whose orbits lie outside that of Mars. The outer planets are large gas giants. Compare inner planet. See also superior planet.