fallout vs outcome

fallout and outcome both are nouns.

Word	Noun	Adjective	Verb	Adverb
fallout	Yes	No	No	No
outcome	Yes	No	No	No

As nouns, outcome is a hypernym of fallout; that is, outcome is a word with a broader meaning than fallout:

fallout: any adverse and unwanted secondary effect
outcome: a phenomenon that follows and is caused by some previous phenomenon

Other hypernyms of fallout include consequence, effect, event, issue, result, upshot.

fallout (noun)	outcome (noun)
any adverse and unwanted secondary effect	something that results
the radioactive particles that settle to the ground after a nuclear explosion	a phenomenon that follows and is caused by some previous phenomenon