noun 1 : conjuration (see CONJURE sense 2a) of the spirits of the dead for purposes of magically revealing the future or influencing the course of events 2 : magic, sorcery
The first part of necromancy has its roots in the Greek word nekros, meaning "dead body" or "dead person." The second part has its roots in the Greek word manteuesthai, meaning "to divine, prophesy." Necromancy was practiced in ancient times by the Assyrians, Babylonians, Egyptians, Greeks, Romans, and Etruscans, but in medieval Europe it was condemned by the church and could get you in a bit of trouble.