Negation

n.	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.

Noun	1.	negation - a negative statement; a statement that is a refusal or denial of some other statement
	2.	negation - the speech act of negating
	3.	negation - (logic) a proposition that is true if and only if another proposition is false

NEGATION. Denial. Two negations are construed to mean one affirmation. Dig. 50, 16, 137.

abnegation, abolishment, abolition, absence, annihilation, annulment, antagonism, argumentation, bucking, challenge, choking, choking off, clashing, conflict, contention, contradiction, contraposition, contravention, contraversion, controversy, counteraction, counterworking, crosscurrent, crossing, declension, declination, declinature, declining, denial, deprivation, deracination, difference, disaccord, disaccordance, disagreement, disallowance, disclaimer, disclamation, disconfirmation, discord, discordance, discordancy, discrepancy, disharmony, disobedience, disparity, disproof, disproval, disproving, dissension, dissent, dissidence, dissonance, disunion, disunity, divergence, diversity, elimination, emptiness, eradication, explosion, expose, exposure, extermination, extinction, extinguishment, extirpation, faction, gainsaying, head wind, holding back, impugnation, impugnment, inaccordance, inequality, invalidation, jarring, liquidation, nay, negative, negative answer, negativeness, negativity, nihility, nix, no, nonacceptance, nonbeing, noncompliance, nonconsent, nonentity, nonexistence, nonobservance, nonoccurrence, nonreality, nonsubsistence, not-being, nothingness, nullification, nullity, opposing, opposition, opposure, oppugnancy, oppugnation, purge, rebutment, rebuttal, recantation, redargution, reductio ad absurdum, refusal, rejection, repudiation, repugnance, resistance, retention, rooting out, silencing, snuffing out, standing against, stifling, strangulation, suffocation, suppression, thumbs-down, traversal, turndown, unactuality, undercurrent, unharmoniousness, unreality, unwillingness, uprooting, vacancy, vacuity, vacuum, variance, void, voiding, withholding