Definify.com
Webster 1913 Edition
Black art
Black′ artˊ
.The art practiced by conjurers and witches; necromancy; conjuration; magic.
☞ This name was given in the Middle Ages to necromancy, under the idea that the latter term was derived from
niger
black, instead of νεκρός
, a dead person, and μαντεία
, divination. Wright.