endoderm
noun
en·do·derm ˈen-də-ˌdərm 
1
a
: the innermost of the three primary germ layers of an embryo that is the source of the epithelium of the digestive tract and its derivatives and of the lower respiratory tract
b
: a tissue (such as esophageal or pancreatic tissue) derived from this germ layer
2
: the inner layer of cells of a diploblastic animal (such as a jellyfish or sponge)
endodermal
ˌen-də-ˈdər-məl
adjective 
Word History
Etymology
French endoderme, from end- + Greek derma skin — more at derm-
First Known Use
1861, in the meaning defined at sense 2
Medical Definition
endoderm
noun
en·do·derm ˈen-də-ˌdərm
: the innermost of the three primary germ layers of an embryo that is the source of the epithelium of the digestive tract and its derivatives and of the lower respiratory tract
also : a tissue that is derived from this germ layer