oatcake vs quick bread

oatcake and quick bread both are nouns.

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

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

oatcake: thin flat unleavened cake of baked oatmeal
quick bread: breads made with a leavening agent that permits immediate baking

oatcake (noun)	quick bread (noun)
thin flat unleavened cake of baked oatmeal	breads made with a leavening agent that permits immediate baking