Easton's Bible Dictionary

(Deuteronomy 15:11), i.e., "one who interrogates the dead," as the word literally means, with the view of discovering the secrets of futurity (Comp. 1 Samuel 28:7). (see DIVINATION.)

Noah Webster's New International Dictionary of the English Language

(n.) One who predicts the future by communicating with the dead; a sorcerer; a wizard.