Source : Webster's Revised Unabridged Dictionary (1913)

Undeniable \Un`de*ni"a*ble\, a.
   1. Not deniable; incapable of denial; palpably true;
      indisputable; obvious; as, undeniable evidence.

   2. Unobjectionable; unquestionably excellent; as, a person of
      undeniable connections. [Colloq.] --G. Eliot.

Source : WordNet®

undeniable
     adj : not possible to deny [ant: {deniable}]