Definition of nay :
1. a negative vote; one who votes in the negative.
2. Denial; refusal.
3. No; - a negative answer to a question asked, or a request made, now superseded by no. See Yes.
4. Not this merely, but also; not only so, but; - used to mark the addition or substitution of a more explicit or more emphatic phrase.
5. To refuse.
affirm, of course not, not really, refusal, no way, inasmuch as, no, rejection, on no account/not on any account, besides, precisely, hardly, nope, i.e., indeed, because, by no means, nothing doing, explain, certainly not, yea, truly, look at, since, as, nix, no dice, verily, not