failure vs relapsing

failure and relapsing both are nouns.

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

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

failure (noun)	relapsing (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