germ layer vs endoderm

germ layer and endoderm both are nouns.

Word	Noun	Adjective	Verb	Adverb
germ layer	Yes	No	No	No
endoderm	Yes	No	No	No

As nouns, endoderm is a hyponym of germ layer; that is, endoderm is a word with a more specific, narrower meaning than germ layer:

germ layer: (embryology) any of the 3 layers of cells differentiated in embryos following gastrulation
endoderm: the inner germ layer that develops into the lining of the digestive and respiratory systems

Other hyponyms of germ layer include ectoblast, ectoderm, exoderm, mesoblast, mesoderm, endoblast, entoblast, entoderm, hypoblast.

germ layer (noun)	endoderm (noun)
(embryology) any of the 3 layers of cells differentiated in embryos following gastrulation	the inner germ layer that develops into the lining of the digestive and respiratory systems