improvement vs decline

improvement and decline both are nouns.

Word	Noun	Adjective	Verb	Adverb
improvement	Yes	No	No	No
decline	Yes	No	Yes	No

improvement (noun)	decline (noun)
the act of improving something	a downward slope or bend
a change for the better; progress in development	a gradual decrease; as of stored charge or current
a condition superior to an earlier condition	change toward something smaller or lower
	a condition inferior to an earlier condition; a gradual falling off from a better state; decline

improvement (verb)	decline (verb)
	grow smaller
	grow worse
	show unwillingness towards
	inflect for number, gender, case, etc.
	go down
	fall in value
	not accept as true