flash in the pan vs failure

flash in the pan and failure both are nouns.

Word	Noun	Adjective	Verb	Adverb
flash in the pan	Yes	No	No	No
failure	Yes	No	No	No

As nouns, failure is a hypernym of flash in the pan; that is, failure is a word with a broader meaning than flash in the pan:

Other hypernyms of flash in the pan include loser, nonstarter, unsuccessful person.

flash in the pan (noun)	failure (noun)
someone who enjoys transient success but then fails	an act that fails
	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