forgive vs excuse

forgive is not a noun while excuse is a noun.

Word	Noun	Adjective	Verb	Adverb
forgive	No	No	Yes	No
excuse	Yes	No	Yes	No

As verbs, excuse is a hyponym of forgive; that is, excuse is a word with a more specific, narrower meaning than forgive:

Other hyponyms of forgive include condone, absolve, free, absolve, shrive, remit, pardon, pardon.

forgive (noun)	excuse (noun)
	a poor example
	a defense of some offensive behavior or some failure to keep a promise etc.
	a note explaining an absence

forgive (verb)	excuse (verb)
stop blaming or grant forgiveness	accept an excuse for
absolve from payment	defend, explain, clear away, or make excuses for by reasoning
	excuse, overlook, or make allowances for; be lenient with
	serve as a reason or cause or justification of
	grant exemption or release to
	ask for permission to be released from an engagement