Definition of Chorion
Chorion: The outermost of the two fetal membranes (the amnion is the innermost) that surround the embryo. The chorion develops villi (vascular finger-like projections) and develops into the placenta.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 3/19/2012
Drug Medical Dictionary of Terms by Letter
Medical Dictionary Term:
Parenting and Pregnancy
Get tips for baby and you.