breakdown vs outage

breakdown and outage both are nouns.

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

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

Other hyponyms of breakdown include brake failure, engine failure, dud, misfire, power failure, power outage, fault.

breakdown (noun)	outage (noun)
the act of disrupting an established order so it fails to continue	a temporary suspension of operation (as of computers)
an analysis into mutually exclusive categories	the amount of something (as whiskey or oil) lost in storage or transportation
a cessation of normal operation
(biology) the process of decay caused by bacterial or fungal action
(chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance
a mental or physical breakdown