Word

amniotic sac, n.

thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
<noun.animal>

amnion amnios amniotic sac

lexical pointers

derivationally related form

amnic amnionic amniotic

semantic pointers

part holonym

amniote fetal membrane

hypernym

sac

domain of synset (topic)

mammal, mammalian