exorciser vs necromancer

exorciser and necromancer both are nouns.

Word	Noun	Adjective	Verb	Adverb
exorciser	Yes	No	No	No
necromancer	Yes	No	No	No

As nouns, necromancer is a hypernym of exorciser; that is, necromancer is a word with a broader meaning than exorciser:

Other hypernyms of exorciser include magician, sorcerer, thaumaturge, thaumaturgist, wizard.

exorciser (noun)	necromancer (noun)
someone who practices exorcism	one who practices magic or sorcery
	one who practices divination by conjuring up the dead