a. 1. Not deniable; incapable of denial; palpably true; indisputable; obvious; as, undeniable evidence. [ 1913 Webster ]
2. Unobjectionable; unquestionably excellent; as, a person of undeniable connections. [ Colloq. ] G. Eliot. [ 1913 Webster ]
adv. In an undeniable manner. [ 1913 Webster ]