Source : Webster's Revised Unabridged Dictionary (1913)

Prerogative \Pre*rog"a*tive\, n. [F. pr['e]rogative, from L.
   praerogativa precedence in voting, preference, privilege, fr.
   praerogativus that is asked before others for his opinion,
   that votes before or first, fr. praerogare to ask before
   another; prae before + rogare to ask. See {Rogation}.]
   1. An exclusive or peculiar privilege; prior and indefeasible
      right; fundamental and essential possession; -- used
      generally of an official and hereditary right which may be
      asserted without question, and for the exercise of which
      there is no responsibility or accountability as to the
      fact and the manner of its exercise.

            The two faculties that are the prerogative of man --
            the powers of abstraction and imagination. --I.
                                                  Taylor.

            An unconstitutional exercise of his prerogative.
                                                  --Macaulay.

   2. Precedence; pre["e]minence; first rank. [Obs.]

            Then give me leave to have prerogative. --Shak.

   Note: The term came into general use in the conflicts between
         the Crown and Parliaments of Great Britain, especially
         in the time of the Stuarts.

   {Prerogative Court} (Eng. Law), a court which formerly had
      authority in the matter of wills and administrations,
      where the deceased left bona notabilia, or effects of the
      value of five pounds, in two or more different dioceses.
      --Blackstone.

   {Prerogative office}, the office in which wills proved in the
      Prerogative Court were registered.

   Syn: Privilege; right. See {Privilege}.

Source : WordNet®

prerogative
     n : a right reserved exclusively by a particular person or group
         (especially a hereditary or official right); "suffrage
         was the prerogative of white adult males" [syn: {privilege},
          {perquisite}, {exclusive right}]