Source : Webster's Revised Unabridged Dictionary (1913)

Masterful \Mas"ter*ful\, a.
   1. Inclined to play the master; domineering; imperious;
      arbitrary. --Dryden.

   2. Having the skill or power of a master; indicating or
      expressing power or mastery.

            His masterful, pale face.             --Mrs.
                                                  Browning.

Source : WordNet®

masterful
     adj 1: having or revealing supreme mastery or skill; "a consummate
            artist"; "consummate skill"; "a masterful speaker";
            "masterful technique"; "a masterly performance of the
            sonata"; "a virtuoso performance" [syn: {consummate},
            {masterly}, {virtuoso(a)}]
     2: able to deal authoritatively with affairs; "dismissed the
        matter with an imperious wave of her hand" [syn: {imperious}]