failing vs failure

failing and failure both are nouns.

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

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

failing (noun)	failure (noun)
failure to reach a minimum required performance	an act that fails
a flaw or weak point	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

failing (adjective)	failure (adjective)
below acceptable in performance