Not

• POS: Adverb

CIDE DICTIONARY

Not,  [Contr. from ne wot. See 2d Note.].

 Wot not; know not; knows not.  Chaucer.  [1913 Webster]

Not, a. 

 Shorn; shaven.  [1913 Webster]

Not, adv. [OE. not, noht, nought, naught, the same word as E. naught. See Naught.].

 A word used to express negation, prohibition, denial, or refusal.  [1913 Webster]
"Not one word spake he more than was need."  [1913 Webster]
"Thou shalt not steal."  [1913 Webster]
"Thine eyes are upon me, and I am not."  [1913 Webster]
"The question is, may I do it, or may I not do it?"  [1913 Webster]

Not . . . but, or Not but, only. [Obs. or Colloq.] Chaucer.

OXFORD DICTIONARY

Not, adv. expressing negation, esp.:
1 (also n't joined to a preceding verb) following an auxiliary verb or be or (in a question) the subject of such a verb (I cannot say; she isn't there; didn't you tell me?; am I not right?; aren't we smart?).

Idiom

not at all (in polite reply to thanks) there is no need for thanks. not but what archaic
1 all the same; nevertheless (I cannot do it; not but what a stronger man might).
2 not such ... or so ... that ... not (not such a fool but what he can see it). not half see HALF. not least with considerable importance, notably. not much see MUCH.
not quite
1 almost (am not quite there).
2 noticeably not (not quite proper). not that (foll. by clause) it is not to be inferred that (if he said so - not that he ever did - he lied). not a thing nothing at all. not very see VERY.

Usage

Use with other verbs is now archaic (I know not; fear not), except with participles and infinitives (not knowing, I cannot say; we asked them not to come).
2 used elliptically for a negative sentence or verb or phrase (Is she coming? -- I hope not; Do you want it? -- Certainly not!).
3 used to express the negative of other words (not a single one was left; Are they pleased? - Not they; he is not my cousin, but my nephew).

Etymology

ME contr. of NOUGHT

ROGET THESAURUS

Not

Negation

N negation, abnegation, denial, disavowal, disclaimer, abjuration, contradiction, contravention, recusation, protest, recusancy, flat contradiction, emphatic contradiction, emphatic denial, dementi, qualification, repudiation, retraction, confutation, refusal, prohibition, denying, denied, contradictory, negative, negatory, recusant, at issue upon, no, nay, not, nowise, not a bit, not a whit, not a jot, not at all, nohow, not in the least, not so, negative, negatory, no way, no such thing, nothing of the kind, nothing of the sort, quite the contrary, tout au contraire, far from it, tant s'en faut, on no account, in no respect, by no, by no manner of means, negatively, never, never in a million years, at no time, there never was a greater mistake, I know better, non haec in faedera, a thousand times no.