the vascular fetal membrane that lies below the chorion and develops from the hindgut in many embryonic higher vertebrates (reptiles, birds and mammals)
ALLANTOIS is a
9
letter word starting with
A
and ending with
S
Definitions & Synonyms
noun -
ALLANTOIS is a sac-like structure involved in nutrition and excretion that develops in the embryos of reptiles, birds, and mammals.