The Collaborative International Dictionary of English v.0.48:

Overturn \O`ver*turn"\, v. t. [imp. & p. p. Overturned; p. pr.
   & vb. n. Overturning.]
   1. To turn or throw from a basis, foundation, or position; to
      overset; as, to overturn a carriage or a building.
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   2. To subvert; to destroy; to overthrow.
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   3. To overpower; to conquer. --Milton.
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   Syn: To demolish; overthrow. See Demolish.
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