butchery vs slaying

butchery and slaying both are nouns.

Word	Noun	Adjective	Verb	Adverb
butchery	Yes	No	No	No
slaying	Yes	No	No	No

As nouns, slaying is a hypernym of butchery; that is, slaying is a word with a broader meaning than butchery:

Other hypernyms of butchery include execution, murder.

butchery (noun)	slaying (noun)
the business of a butcher	unlawful premeditated killing of a human being by a human being
the savage and excessive killing of many people
a building where animals are butchered