The Collaborative International Dictionary of English v.0.48:

Overrule \O`ver*rule"\, v. t. [imp. & p. p. Overruled; p. pr.
   & vb. n. Overruling.]
   1. To rule over; to govern or determine by superior
      authority.
      [1913 Webster]

   2. To rule or determine in a contrary way; to decide against;
      to abrogate or alter; as, God overrules the purposes of
      men; the chairman overruled the point of order.
      [1913 Webster]

            His passion and animosity overruled his conscience.
                                                  --Clarendon.
      [1913 Webster]

            These [difficulties] I had habitually overruled.
                                                  --F. W.
                                                  Newman.
      [1913 Webster]

   3. (Law) To supersede, reject, annul, or rule against; as,
      the plea, or the decision, was overruled by the court.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Overrule \O`ver*rule"\, v. i.
   To be superior or supreme in rulling or controlling; as, God
   rules and overrules. --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

overrule
    v 1: rule against; "The Republicans were overruled when the
         House voted on the bill" [syn: overrule, overturn,
         override, overthrow, reverse]