Negation \Ne*ga"tion\, n. [L. negatio, fr. negare to say no, to deny; ne not + the root of aio I say; cf. Gr. ?, Skr. ah to say; cf. F. n['e]gation. See No, adv., and cf. Adage, Deny, Renegade.]

1. The act of denying; assertion of the nonreality or untruthfulness of anything; declaration that something is not, or has not been, or will not be; denial; -- the opposite of affirmation.

Our assertions and negations should be yea and nay. --Rogers.

2. (Logic) Description or definition by denial, exclusion, or exception; statement of what a thing is not, or has not, from which may be inferred what it is or has.

Source: Webster's Revised Unabridged Dictionary (1913)