refusal vs denial

refusal and denial both are nouns.

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

As nouns, denial is a hypernym of refusal; that is, denial is a word with a broader meaning than refusal:

refusal (noun)	denial (noun)
a message refusing to accept something that is offered	a defendant's answer or plea denying the truth of the charges against him
the act of refusing	renunciation of your own interests in favor of the interests of others
	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