harmfulness vs morbidity

harmfulness and morbidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
harmfulness	Yes	No	No	No
morbidity	Yes	No	No	No

As nouns, morbidity is a hypernym of harmfulness; that is, morbidity is a word with a broader meaning than harmfulness:

Other hypernyms of harmfulness include morbidness, unwholesomeness.

harmfulness (noun)	morbidity (noun)
destructiveness that causes harm or injury	the quality of being unhealthful and generally bad for you
the quality of being noxious	an abnormally gloomy or unhealthy state of mind
	the relative incidence of a particular disease