What is "chorioallantois"

chorioallantois \chorioallantois\ n. a very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois.

Syn: chorioallantoic membrane. [WordNet 1.5] ||

n. (context anatomy English) The vascular extraembryonic membrane, formed by the fusion of the allantois and the chorion, that makes up the placenta in most mammals; the chorioallantoic membrane

n. very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois [syn: chorioallantoic membrane]