reversion vs failure

reversion and failure both are nouns.

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

As nouns, failure is a hypernym of reversion; that is, failure is a word with a broader meaning than reversion:

reversion (noun)	failure (noun)
a failure to maintain a higher state	an act that fails
turning in the opposite direction	an unexpected omission
returning to a former state	an event that does not accomplish its intended purpose
(genetics) a return to a normal phenotype (usually resulting from a second mutation)	a person with a record of failing; someone who loses consistently
a reappearance of an earlier characteristic	lack of success
(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)	loss of ability to function normally
	inability to discharge all your debts as they come due