heal vs scab

heal is not a noun while scab is a noun.

Word	Noun	Adjective	Verb	Adverb
heal	No	No	Yes	No
scab	Yes	No	Yes	No

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

Other hyponyms of heal include skin over, granulate.

heal (noun)	scab (noun)
	the crustlike surface of a healing skin lesion
	someone who works (or provides workers) during a strike

heal (verb)	scab (verb)
get healthy again	form a scab
provide a cure for, make healthy again	take the place of work of someone on strike
heal or recover