Emily Dickinson Lexicon

GAIN-SAY', v.t. [Sax. gean, or ongean, and say; Eng. against; Sw. igen; Dan. gien, igien. See Again, 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 xxi.