The Collaborative International Dictionary of English v.0.48:

thaumaturgist \thau`ma*tur"gist\ (th[add]`m[.a]*t[^u]r"j[i^]st),
   n.
   One who deals in wonders, or believes in them; a wonder
   worker; a thaumaturge. --Carlyle.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

thaumaturgist
    n 1: one who practices magic or sorcery [syn: sorcerer,
         magician, wizard, necromancer, thaumaturge,
         thaumaturgist]