/ Dictionary / Index C chorionic villus: Meaning and Definition of Find definitions for: cho'rion'ic vil'lus Pronunciation: [key] — Embryol. Embryol. one of the branching outgrowths of the chorion that, together with maternal tissue, form the placenta. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. chorionic gonadotropin chorionic villus sampling Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language