black art vs black magic

black art and black magic both are nouns.

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

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

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

Other synonyms of black art include necromancy, sorcery.

black art (noun)	black magic (noun)
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