chorioallantois

n.
The highly vascular fetal membrane that consists of the fused chorion and allantois, found adjacent to the eggshell in reptiles and birds and constituting the placenta in most mammals.

chorioallantoic cho'ri·o·al'lan·to'ic (-ō-ăl'ən-tō'ĭk) adj.

(kôr'ē-ō'ə-lăn'tō-ĭs)
n.

The highly vascular extraembryonic membrane formed by the fusion of the allantois with the chorion that constitutes the placenta in most mammals.

cho'ri·o·al'lan·to'ic (-ō-ăl'ən-tō'ĭk) adj.

An extraembryonic structure formed by union of the chorion and allantois, which by means of vessels in the associated mesoderm serves in gas exchange; in many mammals, it forms the placenta.

Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois
  Synonym: chorioallantois

---