terrestrial planet

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of the four planets, Mercury, Venus, Earth, and Mars, whose orbits are closest to the sun.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any planet of the solar system or any exoplanet which is "Earth-like" in the sense that it is composed primarily of metals and rock, in contrast to a planet which is a gas giant.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a planet having a compact rocky surface like the Earth's; the four innermost planets in the solar system