negation

noun

(uncountable) The act of negating something
(countable) A denial or contradiction
(logic, countable) A proposition which is the contradictory of another proposition and which can be obtained from that other proposition by the appropriately placed addition/insertion of the word "not". (Or, in symbolic logic, by prepending that proposition with the symbol for the logical operator "not".)
change or action with an opposite effect to a previous action
grammatical form that encodes negative polarity or falsity
be less than zero; go in a direction opposite of positive