terrestrial planet definition by American Heritage Dictionary
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Any of the four planets, Mercury, Venus, Earth, or Mars, that are nearest the sun and have similar size and density.
terrestrial planet - Science Definition
See inner planet.