sharpener vs sharpen

sharpener is a noun but sharpen is not a noun.

Word	Noun	Adjective	Verb	Adverb
sharpener	Yes	No	No	No
sharpen	No	No	Yes	No

sharpener (noun)	sharpen (noun)
any implement that is used to make something (an edge or a point) sharper

sharpener (verb)	sharpen (verb)
	become sharp or sharper
	make crisp or more crisp and precise
	raise the pitch of (musical notes)
	put (an image) into focus
	make (one's senses) more acute
	give a point to
	make sharp or sharper
	make (images or sounds) sharp or sharper