chorioallantois

[ kawr-ee-oh-uh-lan-toh-is, ‑tois, kohr‑ ]

noun

, Embryology, Zoology.

1. a vascular, extraembryonic membrane of birds, reptiles, and certain mammals, formed by the fusion of the wall of the chorion with the wall of the allantois.

Other Words From

• chori·o·allan·toic [‑-al-, uh, n-, toh, -ik], adjective

Word History and Origins

Origin of chorioallantois¹

First recorded in 1930–35