9 letters · 9 points in Scrabble
noun the vascular fetal membrane that lies below the chorion and develops from the hindgut in many embryonic higher vertebrates (reptiles, birds and mammals)
originAncient Greek ἀλλαντοειδής (allantoeidḗs, “sausage-shaped”). Compare Greek αλλαντικό (allantikó).
Etymology from Wiktionary, CC BY-SA 3.0