a membranous pouch with a rich blood supply in the embryos of birds, reptiles, and mammals: it is an organ of respiration and excretion for embryonic birds and reptiles: in mammals it helps form the placenta
Origin of allantoisModern Latin from Classical Greek allantoeid?s, sausage-shaped from allas, sausage (prob. from dialect, dialectal all?, garlic, via Oscan an unverified form allo from Classical Latin alium, allium) + -eid?s, -oid
A membranous sac that develops from the posterior part of the digestive tract in the embryos of mammals, birds, and reptiles. It is important in the formation of the umbilical cord and placenta in mammals. Also called allantoid .
Origin of allantoisNew Latin allāntois variant of allāntoīdēs from Greek allāntoeidēs sausage-shaped allās allānt- sausage ( perhaps from Greek dialectal (Magna Graecia) allāwent- (sausage) seasoned with garlic ) ( from allā- garlic ) ( of Italic origin) (Latin ālium garlic ; see allium . ) -oeidēs -oid
(plural allantoises or allantoides)