necromancy

noun

1. (countable, uncountable)Divination involving the dead or death.

   “And for to make this treatise the more pleasaunt and facill, I have put it in forme of a Dialogue, which I have diuided into three bookes: The first speaking of Magie in general, and Necromancie in special.”

   “And in one word for all, Nagomancy, or Necromancy; by inspecting, consulting, and divining by, with, or from the dead.”

   “1867 E. Rogers, quoted in K. Thomas Relig. & Decline of Magic the Devil did often tempt me to study necromancy and nigromancy and to make use of magic, and to make a league with him...”

   “There is no doubt..that necromancy is the touch-stone of occultism...”

2. (countable, uncountable)Loosely, any sorcery or witchcraft, especially involving death or the dead, particularly sorcery involving raising or reanimating the dead.
3. (Internet, countable, uncountable)Synonym of necroposting.