defusing vs ending

defusing and ending both are nouns.

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

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

Other hypernyms of defusing include conclusion, termination.

defusing (noun)	ending (noun)
the act of deactivating or making ineffective (as a bomb)	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