Brian Lumley defined necromancers in his Necroscope books as people who could learn the secrets of the dead by mutilating their corpses causing their still sentient spirits excruciating agony (they can't die again...). In his books this was a skill resurrected by the soviets

Study of black magic and bringing back the dead -the study and rituals for life and death ;romancing the dead back to life and gaining power - getting off on or in a dead warm or cold corpse

1. A gothic fantasy character sporting an outfit too fantastic and ridiculous to be worn in real life.

2. One who conjures the spirits of the dead for purposes of magically revealing the future or influencing the course of events.

A person who collects dead bodies for study purposes, or in hopes of reanimating them someday.

1. A person who uses necromancy to communicate with the dead.
2. A member of one or more cults for the same purpose.
3. A gothic teenager with necromantic tendencies.
4. A book supposedly written between 500 B.C and 1500 A.D and copied a dozen times, of which only one copy exists still, and is apparently in the Vatican Library. (Concerns Satanic Necromancy.)

Someone who kills stuff with dead things.
A necromancer is a sorcerer who specializes in fighting with hordes of undead creatures. Generally found in video games or in old stories

One who gets (or seems to get) all their advice from dead people.