fail vs malfunction

fail is not a noun while malfunction is a noun.

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

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

Other hyponyms of fail include crash, go down, blow, blow out, burn out, misfire, misfunction.

fail (noun)	malfunction (noun)
	a failure to function normally

fail (verb)	malfunction (verb)
stop operating or functioning	fail to function or function improperly
deteriorate
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