brownie vs biscuit

brownie and biscuit both are nouns.

Word	Noun	Adjective	Verb	Adverb
brownie	Yes	No	No	No
biscuit	Yes	No	No	No

As nouns, biscuit is a hypernym of brownie; that is, biscuit is a word with a broader meaning than brownie:

Other hypernyms of brownie include cookie, cooky.

brownie (noun)	biscuit (noun)
square or bar of very rich chocolate cake usually with nuts	small round bread leavened with baking-powder or soda
(folklore) fairies that are somewhat mischievous	any of various small flat sweet cakes