NOT

[not] adv [ME, alter. of nought, fr. nought, pron.--more at naught] (13c) 1--used as a function word to make negative a group of words or a word 2--used as a function word to stand for the negative of a preceding group of words "is sometimes hard to see and sometimes ~" NOT n [not] (1947): a logical operator that produces a statement that is the inverse of an input statement