flaw vs failing

flaw and failing both are nouns.

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

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

Other hypernyms of flaw include weakness.

flaw (noun)	failing (noun)
an imperfection in an object or machine	failure to reach a minimum required performance
defect or weakness in a person's character	a flaw or weak point
an imperfection in a plan or theory or legal document that causes it to fail or that reduces its effectiveness

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

flaw (verb)	failing (verb)
add a flaw or blemish to; make imperfect or defective