Brussels biscuit vs rusk

Brussels biscuit and rusk both are nouns.

Word	Noun	Adjective	Verb	Adverb
Brussels biscuit	Yes	No	No	No
rusk	Yes	No	No	No

As nouns, Brussels biscuit and rusk are synonyms defined as:

Brussels biscuit and rusk: slice of sweet raised bread baked again until it is brown and hard and crisp

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

Brussels biscuit (noun)	rusk (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