necromancy vs black art

necromancy and black art both are nouns.

Word	Noun	Adjective	Verb	Adverb
necromancy	Yes	No	No	No
black art	Yes	No	No	No

As nouns, necromancy and black art are synonyms defined as:

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

Other synonyms of necromancy include black magic, sorcery.

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