cruelty vs ill-usage

cruelty and ill-usage both are nouns.

Word	Noun	Adjective	Verb	Adverb
cruelty	Yes	No	No	No
ill-usage	Yes	No	No	No

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

Other hypernyms of cruelty include abuse, ill-treatment, maltreatment.

cruelty (noun)	ill-usage (noun)
a cruel act; a deliberate infliction of pain and suffering	cruel or inhumane treatment
the quality of being cruel and causing tension or annoyance
feelings of extreme heartlessness