demise vs ending

demise and ending both are nouns.

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

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

Other hypernyms of demise include end.

demise (noun)	ending (noun)
the time when something ends	the act of ending something
	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

demise (verb)	ending (verb)
transfer by a lease or by a will