Pronunciation: (ni-gā'shun),[key] —n. 1. the act of denying: He shook his head in negation of the charge. 2. a denial: a negation of one's former beliefs. 3. something that is without existence; nonentity.
4. the absence or opposite of something that is actual, positive, or affirmative: Darkness is the negation of light. 5. a negative statement, idea, concept, doctrine, etc.; a contradiction, refutation, or rebuttal: a shameless lie that demands a negation.