Exorcist - Vine's Expository Dictionary of New Testament Words
Exorcist[ 1,,G1845, exorkistes ]
(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.