fulfill vs fit

fulfill is not a noun while fit is a noun.

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

As verbs, fulfill and fit are synonyms defined as:

fulfill and fit: fill, satisfy or meet a want or need or condition or restriction

Other synonyms of fulfill include conform to, fill, fulfil, meet, satisfy.

As verbs, fit is a hyponym of fulfill; that is, fit is a word with a more specific, narrower meaning than fulfill:

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

Other hypernyms of fulfill include conform to, fill, fulfil, fulfill, meet, satisfy.

fulfill (noun)	fit (noun)
	a sudden flurry of activity (often for no obvious reason)
	the manner in which something fits
	a sudden uncontrollable attack
	a display of bad temper

fulfill (adjective)	fit (adjective)
	physically and mentally sound or healthy
	meeting adequate standards for a purpose
	(usually followed by `to' or `for') on the point of or strongly disposed

fulfill (verb)	fit (verb)
fill, satisfy or meet a want or need or condition or restriction	make correspond or harmonize
put in effect	make fit
meet the requirements or expectations of	insert or adjust several objects or people
	fill, satisfy or meet a want or need or condition or restriction
	provide with (something) usually for a specific purpose
	be the right size or shape; fit correctly or as desired
	conform to some shape or size
	be compatible, similar or consistent; coincide in their characteristics
	be agreeable or acceptable to