Nigromancy
Nigromancy is the popular medieval variant of necromancy — etymologically confused with Latin niger (black), generating the popular synonym "black art". In the Middle Ages, nigromancy designated communication with the dead, but also ceremonial magic and demonology in general.
Medieval inquisitorial usage
The Inquisition often accused supposed sorceresses of "nigromancy". The term was used pejoratively to refer to any forbidden magical practice — diluting the original meaning (necromancy).