/ Dictionary / Index A areo-: Meaning and Definition of Find definitions for: areo- Pronunciation: [key] a combining form meaning “the planet Mars,” used in the formation of compound words: areocentric. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. aren't areocentric Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language