Source : Webster's Revised Unabridged Dictionary (1913)

Dictator \Dic*ta"tor\, n. [L.]
   1. One who dictates; one who prescribes rules and maxims
      authoritatively for the direction of others. --Locke.

   2. One invested with absolute authority; especially, a
      magistrate created in times of exigence and distress, and
      invested with unlimited power.

            Invested with the authority of a dictator, nay, of a
            pope, over our language.              --Macaulay.

Source : WordNet®

dictator
     n 1: a speaker who dictates to a secretary or a recording machine
     2: a ruler who is unconstrained by law [syn: {potentate}]
     3: a person behaves in an tyrannical manner; "my boss is a
        dictator who makes everyone work overtime" [syn: {authoritarian}]