fit the bill vs fulfill

fit the bill and fulfill both are verbs.

Word	Noun	Adjective	Verb	Adverb
fit the bill	No	No	Yes	No
fulfill	No	No	Yes	No

As verbs, fulfill is a hypernym of fit the bill; that is, fulfill is a word with a broader meaning than fit the bill:

Other hypernyms of fit the bill include conform to, fill, fit, fulfil, meet, satisfy.

fit the bill (verb)	fulfill (verb)
be what is needed or be good enough for what is required	fill, satisfy or meet a want or need or condition or restriction
	put in effect
	meet the requirements or expectations of