The Collaborative International Dictionary of English v.0.48:

Repudiate \Re*pu"di*ate\ (r[-e]*p[=u]"d[i^]*[=a]t), v. t. [imp.
   & p. p. Repudiated (-?`t?d); p. pr. & vb. n.
   Repudiating.] [L. repudiatus, p. p. of repudiare to
   repudiate, reject, fr. repudium separation, divorce; pref.
   re- re- + pudere to be ashamed.]
   [1913 Webster]
   1. To cast off; to disavow; to have nothing to do with; to
      renounce; to reject.
      [1913 Webster]

            Servitude is to be repudiated with greater care.
                                                  --Prynne.
      [1913 Webster]

   2. To divorce, put away, or discard, as a wife, or a woman
      one has promised to marry.
      [1913 Webster]

            His separation from Terentis, whom he repudiated not
            long afterward.                       --Bolingbroke.
      [1913 Webster]

   3. To refuse to acknowledge or to pay; to disclaim; as, the
      State has repudiated its debts.
      [1913 Webster]

WordNet (r) 3.0 (2006):

repudiate
    v 1: cast off; "She renounced her husband"; "The parents
         repudiated their son" [syn: disown, renounce,
         repudiate]
    2: refuse to acknowledge, ratify, or recognize as valid; "The
       woman repudiated the divorce settlement"
    3: refuse to recognize or pay; "repudiate a debt"
    4: reject as untrue, unfounded, or unjust; "She repudiated the
       accusations"