cruelty vs impalement

cruelty and impalement both are nouns.

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

As nouns, impalement is a hyponym of cruelty; that is, impalement is a word with a more specific, narrower meaning than cruelty:

cruelty: a cruel act; a deliberate infliction of pain and suffering
impalement: the act of piercing with a sharpened stake as a form of punishment or torture

Other hyponyms of cruelty include atrocity, inhumanity.

cruelty (noun)	impalement (noun)
a cruel act; a deliberate infliction of pain and suffering	the act of piercing with a sharpened stake as a form of punishment or torture
the quality of being cruel and causing tension or annoyance
feelings of extreme heartlessness