Source : Webster's Revised Unabridged Dictionary (1913)

Overthrow \O`ver*throw"\, v. t. [imp. {Overthrew}; p. p.
   {Overthrown}; p. pr. & vb. n. {Overthrowing}.]
   1. To throw over; to overturn; to upset; to turn upside down.

            His wife overthrew the table.         --Jer. Taylor.

   2. To cause to fall or to fail; to subvert; to defeat; to
      make a ruin of; to destroy.

            When the walls of Thebes he overthrew. --Dryden.

            [Gloucester] that seeks to overthrow religion.
                                                  --Shak.

   Syn: To demolish; overturn; prostrate; destroy; ruin;
        subvert; overcome; conquer; defeat; discomfit; vanquish;
        beat; rout.

Source : WordNet®

overthrow
     n 1: the termination of a ruler or institution (especially by
          force)
     2: the act of disturbing the mind or body; "his carelessness
        could have caused an ecological upset"; "she was
        unprepared for this sudden overthrow of their normal way
        of living" [syn: {upset}, {derangement}]
     v 1: cause the downfall of; of rulers; "The Czar was overthrown";
          "subvert the ruling class" [syn: {subvert}, {overturn},
          {bring down}]
     2: rule against; "The Republicans were overruled when the House
        voted on the bill" [syn: {overrule}, {overturn}, {override},
         {reverse}]
     [also: {overthrown}, {overthrew}]

overthrew
     See {overthrow}