bullfinch vs finch

bullfinch and finch both are nouns.

Word	Noun	Adjective	Verb	Adverb
bullfinch	Yes	No	No	No
finch	Yes	No	No	No

As nouns, finch is a hypernym of bullfinch; that is, finch is a word with a broader meaning than bullfinch:

bullfinch: common European finch mostly black and white with red throat and breast
finch: any of numerous small songbirds with short stout bills adapted for crushing seeds

bullfinch (noun)	finch (noun)
common European finch mostly black and white with red throat and breast	any of numerous small songbirds with short stout bills adapted for crushing seeds