sharpen vs sharpener

sharpen is not a noun while sharpener is a noun.

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

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

sharpen (verb)	sharpener (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