failure vs relapse

failure and relapse both are nouns.

Word	Noun	Adjective	Verb	Adverb
failure	Yes	No	No	No
relapse	Yes	No	Yes	No

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

failure (noun)	relapse (noun)
an act that fails	a failure to maintain a higher state
an unexpected omission
an event that does not accomplish its intended purpose
a person with a record of failing; someone who loses consistently
lack of success
loss of ability to function normally
inability to discharge all your debts as they come due

failure (verb)	relapse (verb)
	go back to bad behavior
	deteriorate in health