D defs.my
Entry 1 sense Webster, 1913

Allantois

· Al·lan·to·is · IPA /əˈlæntəʊ.ɪs/
01 n. A membranous appendage of the embryos of mammals, birds, and reptiles, -- in mammals serving to connect the fetus with the parent; the urin…
  1. 1.
    A membranous appendage of the embryos of mammals, birds, and reptiles, -- in mammals serving to connect the fetus with the parent; the urinary vesicle.(Anat.)