mesoderm vs germ layer

mesoderm and germ layer both are nouns.

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

As nouns, germ layer is a hypernym of mesoderm; that is, germ layer is a word with a broader meaning than mesoderm:

mesoderm: the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue
germ layer: (embryology) any of the 3 layers of cells differentiated in embryos following gastrulation

mesoderm (noun)	germ layer (noun)
the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue	(embryology) any of the 3 layers of cells differentiated in embryos following gastrulation