Gainsay

GAINSA'Y, verb transitive [Eng. against.] To contradict; to oppose in words; to deny or declare not to be true what another says; to controvert; to dispute; applied to persons, or to propositions, declarations or facts.

I will give you a mouth and wisdom, which all your adversaries shall not be able to gainsay nor resist. [[Luke 21#15|Luke 21:15]].