harden vs cure

harden is not a noun while cure is a noun.

Word	Noun	Adjective	Verb	Adverb
harden	No	No	Yes	No
cure	Yes	No	Yes	No

As verbs, cure is a hyponym of harden; that is, cure is a word with a more specific, narrower meaning than harden:

Other hyponyms of harden include encrust, incrust, callus, calcify.

harden (noun)	cure (noun)
	a medicine or therapy that cures disease or relieve pain

harden (verb)	cure (verb)
become hard or harder	provide a cure for, make healthy again
make hard or harder	prepare by drying, salting, or chemical processing in order to preserve
make healthy	be or become preserved
cause to accept or become hardened to; habituate	make (substances) hard and improve their usability
harden by reheating and cooling in oil