The art of revealing future events by means of a pretended communication with the dead; the black art; hence, magic in general; conjuration; enchantment. See Black art. [1913 Webster]
"This palace standeth in the air,
By necromancy placèd there." [1913 Webster]

necromancy, n.
1 the prediction of the future by the supposed communication with the dead.
2 witchcraft.

Derivative:
necromancer n. necromantic adj.

Etymology:
ME f. OF nigromancie f. med.L nigromantia changed (by assoc. with L niger nigri black) f. LL necromantia f. Gk nekromanteia (as NECRO-, -MANCY)

N  sorcery, occult art, occult sciences, magic, the black art, necromancy, theurgy, thaumaturgy, demonology, demonomy, demonship, diablerie, bedevilment, witchcraft, witchery, glamor, fetishism, fetichism, feticism, ghost dance, hoodoo, obi, obiism, voodoo, voodooism, Shamanism (Esquimaux), vampirism, conjuration, bewitchery, exorcism, enchantment, mysticism, second sight, mesmerism, animal magnetism, od force, odylic force, electrobiology, clairvoyance, spiritualism, spirit rapping, table turning, divination, sortilege, ordeal, sortes Virgilianae, hocus-pocus, magic, magical, mystic, weird, cabalistic, talismanic, phylacteric, incantatory, charmed, Circean, odylic, voodoo.

N  prediction, announcement, program, programme, premonition, prognosis, prophecy, vaticination, mantology, prognostication, premonstration, augury, auguration, ariolation, hariolation, foreboding, aboding, bodement, abodement, omniation, omniousness, auspices, forecast, omen, horoscope, nativity, sooth, soothsaying, fortune telling, crystal gazing, divination, necromancy, astrology, horoscopy, judicial astrology, adytum prefiguration, prefigurement, prototype, type, oracle, predicting, predictive, prophetic, fatidic, fatidical, vaticinal, oracular, fatiloquent, haruspical, Sibylline, weatherwise, ominous, portentous, augurous, augurial, augural, auspicial, auspicious, prescious, monitory, extispicious, premonitory, significant of, pregnant with, bit with the fate of, coming events cast their shadows before, dicamus bona verba, there buds the promise of celestial worth, by oracles, Theomancy, by the Bible, Bibliomancy, by ghosts, Psychomancy, by crystal gazing, Crystallomancy, by shadows or manes, Sciomancy, by appearances in the air, Aeromancy, Chaomancy, by the stars at birth, Genethliacs, by meteors, Meteoromancy, by winds, Austromancy, by sacrificial appearances, Aruspicy, Haruspicy, Hieromancy, Hieroscopy, by the entrails of animals sacrificed, Extispicy, Hieromancy, by the entrails of a human sacrifice, Anthropomancy, by the entrails of fishes, Ichthyomancy, by sacrificial fire, Pyromancy, by red-hot iron, Sideromancy, by smoke from the altar, Capnomancy, by mice, Myomancy, by birds, Orniscopy, Ornithomancy, by a cock picking up grains, Alectryomancy, Alectromancy, by fishes, Ophiomancy, by herbs, Botanomancy, by water, Hydromancy, by fountains, Pegomancy, by a wand, Rhabdomancy, by dough of cakes, Crithomancy, by meal, Aleuromancy, Alphitomancy, by salt, Halomancy, by dice, Cleromancy, by arrows, Belomancy, by a balanced hatchet, Axinomancy, by a balanced sieve, Coscinomancy, by a suspended ring, Dactyliomancy, by dots made at random on paper, Geomancy, by precious stones, Lithomancy, by pebbles, Pessomancy, by pebbles drawn from a heap, Psephomancy, by mirrors, Catoptromancy, by writings in ashes, Tephramancy, by dreams, Oneiromancy, by the hand, Palmistry, Chiromancy, by nails reflecting the sun's rays, Onychomancy, by finger rings, Dactylomancy, by numbers, Arithmancy, by drawing lots, Sortilege, by passages in books, Stichomancy, by the letters forming the name of the person, Onomancy, Nomancy, by the features, Anthroposcopy, by the mode of laughing, Geloscopy, by ventriloquism, Gastromancy, by walking in a circle, Gyromancy, by dropping melted wax into water, Ceromancy, by currents, Bletonism, by the color and peculiarities of wine, Oenomancy.