Exorcist
Vine's Expository Dictionary of NT Words [1]
denotes (a) "one who administers an oath;" (b) "an exorcist" (akin to exorkizo, "to adjure," from orkos, "an oath"), "one who empolys a formula of conjuration for the expulsion of demons," Acts 19:13 . The practice of "exorcism" was carried on by strolling Jews, who used their power in the recitation of particular names.
Smith's Bible Dictionary [2]
Exorcist. One who pretends to expel evil spirits by conjuration, prayers and ceremonies. Exorcism was frequently practiced among the Jews. Matthew 12:27; Acts 19:13. David, by playing skillfully on a harp, procured the temporary departure of the evil spirit which troubled Saul. 1 Samuel 16:23. The power of casting out devils was bestowed by Christ while on earth upon the apostles, Matthew 10:8, and the seventy disciples Luke 10:17-19 and was, according to his promise, Mark 16:17, exercised by believers after his ascension. Acts 16:18.
Easton's Bible Dictionary [3]
Acts 19:13 Matthew 12:27 Mark 9:38 Luke 9:49,50
The power of casting out devils was conferred by Christ on his apostles ( Matthew 10:8 ), and on the seventy ( Luke 10:17-19 ), and was exercised by believers after his ascension ( Mark 16:17; Acts 16:18 ); but this power was never spoken of as exorcism.
Webster's Dictionary [4]
(1): ( n.) One who expels evil spirits by conjuration or exorcism.
(2): ( n.) A conjurer who can raise spirits.