What does "allantois" mean?

A sac, having a number of functions, that develops in the alimentary canal of the embryos of mammals, birds and reptiles.

What is a synonym for "allantois"?

Common synonyms include: allantoic sac, allantoic sac, allantoid, allantoid, sausage.

Pronounced //əˈlæntəʊ.ɪs//.

//əˈlæntəʊ.ɪs// noun

noun ·Rare ·Advanced level

Noun

1
A sac, having a number of functions, that develops in the alimentary canal of the embryos of mammals, birds and reptiles.
2
the vascular fetal membrane that lies below the chorion and develops from the hindgut in many embryonic higher vertebrates (reptiles, birds and mammals) wordnet

Ancient Greek ἀλλαντοειδής (allantoeidḗs, “sausage-shaped”). Compare Greek αλλαντικό (allantikó).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.