outcome vs ending

outcome and ending both are nouns.

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

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

Other hypernyms of outcome include conclusion, finish.

outcome (noun)	ending (noun)
something that results	the act of ending something
a phenomenon that follows and is caused by some previous phenomenon	the end of a word (a suffix or inflectional ending or final morpheme)
	the last section of a communication
	event whose occurrence ends something
	the point in time at which something ends