failure vs breakdown

failure and breakdown both are nouns.

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

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

failure (noun)	breakdown (noun)
an act that fails	the act of disrupting an established order so it fails to continue
an unexpected omission	an analysis into mutually exclusive categories
an event that does not accomplish its intended purpose	a cessation of normal operation
a person with a record of failing; someone who loses consistently	(biology) the process of decay caused by bacterial or fungal action
lack of success	(chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance
loss of ability to function normally	a mental or physical breakdown
inability to discharge all your debts as they come due