wafer vs biscuit

wafer and biscuit both are nouns.

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

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

Other hypernyms of wafer include cookie, cooky.

wafer (noun)	biscuit (noun)
a small thin crisp cake or cookie	small round bread leavened with baking-powder or soda
thin disk of unleavened bread used in a religious service (especially in the celebration of the Eucharist)	any of various small flat sweet cakes
a small adhesive disk of paste; used to seal letters