disaffirmation vs assertion

disaffirmation and assertion both are nouns.

Word	Noun	Adjective	Verb	Adverb
disaffirmation	Yes	No	No	No
assertion	Yes	No	No	No

As nouns, assertion is a hypernym of disaffirmation; that is, assertion is a word with a broader meaning than disaffirmation:

disaffirmation: the act of asserting that something alleged is not true
assertion: a declaration that is made emphatically (as if no supporting evidence were necessary)

Other hypernyms of disaffirmation include asseveration, averment.

disaffirmation (noun)	assertion (noun)
the act of asserting that something alleged is not true	a declaration that is made emphatically (as if no supporting evidence were necessary)
	the act of affirming or asserting or stating something