tunica vs tissue layer

tunica and tissue layer both are nouns.

Word	Noun	Adjective	Verb	Adverb
tunica	Yes	No	No	No
tissue layer	Yes	No	No	No

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

tunica: an enveloping or covering membrane or layer of body tissue
tissue layer: a pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants

Other hypernyms of tunica include membrane.

tunica (noun)	tissue layer (noun)
an enveloping or covering membrane or layer of body tissue	a pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants