Boston brown bread vs bread

Boston brown bread and bread both are nouns.

Word	Noun	Adjective	Verb	Adverb
Boston brown bread	Yes	No	No	No
bread	Yes	No	Yes	No

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

Boston brown bread: dark steamed bread made of cornmeal wheat and flour with molasses and soda and milk or water
bread: food made from dough of flour or meal and usually raised with yeast or baking powder and then baked

Other hypernyms of Boston brown bread include breadstuff, staff of life.

Boston brown bread (noun)	bread (noun)
dark steamed bread made of cornmeal wheat and flour with molasses and soda and milk or water	food made from dough of flour or meal and usually raised with yeast or baking powder and then baked
	informal terms for money

Boston brown bread (verb)	bread (verb)
	cover with bread crumbs