D defs.my
Entry 2 senses Webster, 1913

Negation

/nəg-āsh'-ən/ · Ne·ga·tion · IPA /nəˈɡeɪʃn̩/
01 n. The act of denying; assertion of the nonreality or untruthfulness of anything; declaration that something is not, or has not been, or will …
  1. 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. 2.
    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.(Logic)