wear on vs decline

wear on is not a noun while decline is a noun.

Word	Noun	Adjective	Verb	Adverb
wear on	No	No	Yes	No
decline	Yes	No	Yes	No

As verbs, decline is a hypernym of wear on; that is, decline is a word with a broader meaning than wear on:

Other hypernyms of wear on include go down, wane.

wear on (noun)	decline (noun)
	a downward slope or bend
	a gradual decrease; as of stored charge or current
	change toward something smaller or lower
	a condition inferior to an earlier condition; a gradual falling off from a better state; decline

wear on (verb)	decline (verb)
pass slowly (of time)	grow smaller
	grow worse
	show unwillingness towards
	inflect for number, gender, case, etc.
	go down
	fall in value
	not accept as true