flub vs fumble

flub and fumble both are nouns.

Word	Noun	Adjective	Verb	Adverb
flub	Yes	No	Yes	No
fumble	Yes	No	Yes	No

As nouns, fumble is a hyponym of flub; that is, fumble is a word with a more specific, narrower meaning than flub:

As verbs, flub and fumble are synonyms defined as:

flub (noun)	fumble (noun)
an embarrassing mistake	(sports) dropping the ball

flub (verb)	fumble (verb)
make a mess of, destroy or ruin	drop or juggle or fail to play cleanly a grounder
	feel about uncertainly or blindly
	handle clumsily
	make one's way clumsily or blindly
	make a mess of, destroy or ruin