cornbread vs quick bread

cornbread and quick bread both are nouns.

Word	Noun	Adjective	Verb	Adverb
cornbread	Yes	No	No	No
quick bread	Yes	No	No	No

As nouns, quick bread is a hypernym of cornbread; that is, quick bread is a word with a broader meaning than cornbread:

cornbread: bread made primarily of cornmeal
quick bread: breads made with a leavening agent that permits immediate baking

cornbread (noun)	quick bread (noun)
bread made primarily of cornmeal	breads made with a leavening agent that permits immediate baking