ENDODERM

endoderm, entoderm, endoblast, entoblast, hypoblast

(noun) the inner germ layer that develops into the lining of the digestive and respiratory systems

Source: WordNet® 3.1

Etymology

Noun

endoderm (plural endoderms)

One of the three tissue layers in the embryo of a metazoan animal. Through development, it will produce the digestive system of the adult.

Source: Wiktionary

En"do*derm, n. Etym: [Endo- + Gr. (Biol.) (a) The inner layer of the skin or integument of an animal. (b) The innermost layer of the blastoderm and the structures derived from it; the hypoblast; the entoblast. See Illust. of Ectoderm.

Source: Webster’s Unabridged Dictionary 1913 Edition