outcome vs decision

outcome and decision both are nouns.

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

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

Other hyponyms of outcome include denouement, deal, aftermath, consequence, separation, sequel, subsequence, worst.

outcome (noun)	decision (noun)
something that results	the act of making up your mind about something
a phenomenon that follows and is caused by some previous phenomenon	the trait of resoluteness as evidenced by firmness of character or purpose
	a position or opinion or judgment reached after consideration
	the outcome of a game or contest
	(boxing) a victory won on points when no knockout has occurred