inhumanity vs cruelty

inhumanity and cruelty both are nouns.

Word	Noun	Adjective	Verb	Adverb
inhumanity	Yes	No	No	No
cruelty	Yes	No	No	No

As nouns, cruelty is a hypernym of inhumanity; that is, cruelty is a word with a broader meaning than inhumanity:

Other hypernyms of inhumanity include inhuman treatment.

inhumanity (noun)	cruelty (noun)
an act of atrocious cruelty	a cruel act; a deliberate infliction of pain and suffering
the quality of lacking compassion or consideration for others	the quality of being cruel and causing tension or annoyance
	feelings of extreme heartlessness