Source : Webster's Revised Unabridged Dictionary (1913)

Monarchy \Mon"arch*y\, n.; pl. {Monarchies}. [F. monarchie, L.
   monarchia, Gr. ?. See {Monarch}.]
   1. A state or government in which the supreme power is lodged
      in the hands of a monarch.

   2. A system of government in which the chief ruler is a
      monarch.

            In those days he had affected zeal for monarchy.
                                                  --Macaulay.

   3. The territory ruled over by a monarch; a kingdom.

            What scourage for perjury Can this dark monarchy
            afford false Clarence.                --Shak.

   {Fifth monarchy}, a universal monarchy, supposed to be the
      subject of prophecy in Daniel ii.; the four preceding
      monarchies being Assyrian, Persian, Grecian, and Roman.
      See {Fifth Monarchy men}, under {Fifth}.

Source : WordNet®

monarchy
     n : an autocracy governed by a monarch who usually inherits the
         authority