twice-baked bread vs zwieback

twice-baked bread and zwieback both are nouns.

Word	Noun	Adjective	Verb	Adverb
twice-baked bread	Yes	No	No	No
zwieback	Yes	No	No	No

As nouns, twice-baked bread and zwieback are synonyms defined as:

twice-baked bread and zwieback: slice of sweet raised bread baked again until it is brown and hard and crisp

Other synonyms of twice-baked bread include Brussels biscuit, rusk.

twice-baked bread (noun)	zwieback (noun)
slice of sweet raised bread baked again until it is brown and hard and crisp	slice of sweet raised bread baked again until it is brown and hard and crisp