decline vs improvement

decline and improvement both are nouns.

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

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

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