necromancy vs witchery

necromancy and witchery both are nouns.

Word	Noun	Adjective	Verb	Adverb
necromancy	Yes	No	No	No
witchery	Yes	No	No	No

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

necromancy: the belief in magical spells that harness occult forces or evil spirits to produce unnatural effects in the world
witchery: the art of sorcery

Other hyponyms of necromancy include witchcraft, bewitchment, enchantment, demonism, diabolism, Satanism, obiism.

necromancy (noun)	witchery (noun)
conjuring up the dead, especially for prophesying	the art of sorcery
the belief in magical spells that harness occult forces or evil spirits to produce unnatural effects in the world