Wiktionary
n. (context astronomy planets English) Any planet of the Solar System whose orbit is located between the asteroid belt and the sun, i.e., any of Mercury, Venus, Earth, or Mars.
Usage examples of "inner planet".
Only the ocean-desert remained, the great Mother Desert of the inner planet, with its rim of thorn bushes, which Fremen still called Queen of Night.
Nothing would be less interesting than the conversion of one inner planet to be like another one.
Calhoun had the inner planet, Canis III, firmly in the center of his forward screen.
She had started her days as an inner planet cruise ship, but had been obsolete for that purpose for a century.
It looked something like a target, with the sun and the orbits of the inner planet crowded together to make a bull's-eye.
They are an inner planet and the men there are satiated with the best of a hundred worlds.
And he sketched a gesture in my direction, which, made by a less brutish body, might have been the formal bow-of-courtesy of an inner planet man.