/ Dictionary / Index C chorio-: Meaning and Definition of Find definitions for: chorio- Pronunciation: [key] a combining form meaning “chorion,” “choroid,” used in the formation of compound words: chorioallantois. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. chorine chorioallantois Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language