The Collaborative International Dictionary of English v.0.48:

Overset \O`ver*set"\, v. t. [imp. & p. p. Overset; p. pr. &
   vb. n. Oversetting. ]
   1. To turn or tip (anything) over from an upright, or a
      proper, position so that it lies upon its side or bottom
      upwards; to upset; as, to overset a chair, a coach, a
      ship, or a building. --Dryden.
      [1913 Webster]

   2. To cause to fall, or to fail; to subvert; to overthrow;
      as, to overset a government or a plot. --Addison.
      [1913 Webster]

   3. To fill too full. [Obs.] --Howell.
      [1913 Webster]