white bread vs staff of life

white bread and staff of life both are nouns.

Word	Noun	Adjective	Verb	Adverb
white bread	Yes	No	No	No
staff of life	Yes	No	No	No

As nouns, staff of life is a hypernym of white bread; that is, staff of life is a word with a broader meaning than white bread:

white bread: bread made with finely ground and usually bleached wheat flour
staff of life: food made from dough of flour or meal and usually raised with yeast or baking powder and then baked

Other hypernyms of white bread include bread, breadstuff.

white bread (noun)	staff of life (noun)
bread made with finely ground and usually bleached wheat flour	food made from dough of flour or meal and usually raised with yeast or baking powder and then baked