Source : Webster's Revised Unabridged Dictionary (1913)

Illuminator \Il*lu"mi*na`tor\, n. [L., an enlightener, LL. also,
   an illuminator of books.]
   1. One whose occupation is to adorn books, especially
      manuscripts, with miniatures, borders, etc. See
      {Illuminate}, v. t., 3.

   2. A condenser or reflector of light in optical apparatus;
      also, an illuminant.