Gain·say v. t. [imp. & p. p. Gainsaid p. pr. & vb. n. Gainsaying.] To contradict; to deny; to controvert; to dispute; to forbid.
I will give you a mouth and wisdom which all your adversaries shall not be able to gainsay nor resist. --Luke xxi. 15.
The just gods gainsay
That any drop thou borrow'dst from thy mother,
My sacred aunt, should by my mortal sword
Be drained. --Shak.