Definitions for black art
Random House Webster's College Dictionary
Often, black arts. witchcraft, sorcery, or other occult practice used for evil purposes.
Origin of black art:
sorcery, black magic, black art, necromancy(noun)
the belief in magical spells that harness occult forces or evil spirits to produce unnatural effects in the world
A practice such as witchcraft, sorcery, necromancy, or black magic.
A process that is mysterious or difficult to master.
the art practiced by conjurers and witches; necromancy; conjuration; magic
The Nuttall Encyclopedia
name given to the presumed power of evoking evil spirits.
The New Hacker's Dictionary
[common] A collection of arcane, unpublished, and (by implication) mostly ad-hoc techniques developed for a particular application or systems area (compare black magic). VLSI design and compiler code optimization were (in their beginnings) considered classic examples of black art; as theory developed they became deep magic, and once standard textbooks had been written, became merely heavy wizardry. The huge proliferation of formal and informal channels for spreading around new computer-related technologies during the last twenty years has made both the term black art and what it describes less common than formerly. See also voodoo programming.