fail vs muff

fail is not a noun while muff is a noun.

Word	Noun	Adjective	Verb	Adverb
fail	No	No	Yes	No
muff	Yes	No	Yes	No

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

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

Other hyponyms of fail include lose track, strike out, default, default on, choke, miss.

fail (noun)	muff (noun)
	(sports) dropping the ball
	a warm tubular covering for the hands

fail (verb)	muff (verb)
stop operating or functioning	make a mess of, destroy or ruin
deteriorate	fail to catch, as of a ball
prove insufficient
disappoint, prove undependable to; abandon, forsake
become bankrupt or insolvent; fail financially and close
be unsuccessful
fail to get a passing grade
fail to do something; leave something undone
judge unacceptable
be unable
fall short in what is expected