denial vs refusal

denial and refusal both are nouns.

Word	Noun	Adjective	Verb	Adverb
denial	Yes	No	No	No
refusal	Yes	No	No	No

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

Other hyponyms of denial include abnegation, naysaying, negative, disavowal, disclaimer.

denial (noun)	refusal (noun)
a defendant's answer or plea denying the truth of the charges against him	a message refusing to accept something that is offered
renunciation of your own interests in favor of the interests of others	the act of refusing
the act of refusing to comply (as with a request)
the act of asserting that something alleged is not true
(psychiatry) a defense mechanism that denies painful thoughts