allantochorion

Term: allantochorion 

Literally meaning: “allantois with chorion”

Origin: Anc Greek
Anc Greek αλλάs/allas(=saugage),  
genitive άλλαντος/allantos because allantois resembles to sausage.
>άλλος/allos(=other) + εντός/entos(=inside) because intestine is filled inside with meat
+χόριον/chorion(=outer membrane of the fetus , leather)
Coined/History

Definition
It is a term for the fusion of embryonic membranes chorion and allantois.