failure vs reversion

failure and reversion both are nouns.

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

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

failure (noun)	reversion (noun)
an act that fails	a failure to maintain a higher state
an unexpected omission	turning in the opposite direction
an event that does not accomplish its intended purpose	returning to a former state
a person with a record of failing; someone who loses consistently	(genetics) a return to a normal phenotype (usually resulting from a second mutation)
lack of success	a reappearance of an earlier characteristic
loss of ability to function normally	(law) an interest in an estate that reverts to the grantor (or his heirs) at the end of some period (e.g., the death of the grantee)
inability to discharge all your debts as they come due