'Black art' definitions:

Definition of 'black art'

From: WordNet
noun
The belief in magical spells that harness occult forces or evil spirits to produce unnatural effects in the world [syn: sorcery, black magic, black art, necromancy]

Definition of 'Black art'

From: GCIDE
  • Black art \Black" art`\ The art practiced by conjurers and witches; necromancy; conjuration; magic. [1913 Webster]
  • Note: This name was given in the Middle Ages to necromancy, under the idea that the latter term was derived from niger black, instead of nekro`s, a dead person, and mantei`a, divination. --Wright. [1913 Webster]