unpardonable vs inexcusable

unpardonable and inexcusable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unpardonable	No	Yes	No	No
inexcusable	No	Yes	No	No

unpardonable (adjective)	inexcusable (adjective)
not admitting of pardon	without excuse or justification
	not excusable