The Collaborative International Dictionary of English v.0.48:

Wit \Wit\ (w[i^]t), v. t. & i. [inf. (To) Wit; pres. sing.
   Wot; pl. Wite; imp. Wist(e); p. p. Wist; p. pr. & vb.
   n. Wit(t)ing. See the Note below.] [OE. witen, pres. ich
   wot, wat, I know (wot), imp. wiste, AS. witan, pres. w[=a]t,
   imp. wiste, wisse; akin to OFries. wita, OS. witan, D. weten,
   G. wissen, OHG. wizzan, Icel. vita, Sw. veta, Dan. vide,
   Goth. witan to observe, wait I know, Russ. vidiete to see, L.
   videre, Gr. ?, Skr. vid to know, learn; cf. Skr. vid to find.
   ????. Cf. History, Idea, Idol, -oid, Twit, Veda,
   Vision, Wise, a. & n., Wot.]
   To know; to learn. "I wot and wist alway." --Chaucer.
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   Note: The present tense was inflected as follows; sing. 1st
         pers. wot; 2d pers. wost, or wot(t)est; 3d pers. wot,
         or wot(t)eth; pl. witen, or wite. The following variant
         forms also occur; pres. sing. 1st & 3d pers. wat, woot;
         pres. pl. wyten, or wyte, weete, wote, wot; imp. wuste
         (Southern dialect); p. pr. wotting. Later, other
         variant or corrupt forms are found, as, in Shakespeare,
         3d pers. sing. pres. wots.
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               Brethren, we do you to wit [make you to know] of
               the grace of God bestowed on the churches of
               Macedonia.                         --2 Cor. viii.
                                                  1.
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               Thou wost full little what thou meanest.
                                                  --Chaucer.
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               We witen not what thing we prayen here.
                                                  --Chaucer.
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               When that the sooth in wist.       --Chaucer.
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   Note: This verb is now used only in the infinitive, to wit,
         which is employed, especially in legal language, to
         call attention to a particular thing, or to a more
         particular specification of what has preceded, and is
         equivalent to namely, that is to say.
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The Collaborative International Dictionary of English v.0.48:

Wit \Wit\, n. [AS. witt, wit; akin to OFries. wit, G. witz, OHG.
   wizz[imac], Icel. vit, Dan. vid, Sw. vett. [root]133. See
   Wit, v.]
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   1. Mind; intellect; understanding; sense.
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            Who knew the wit of the Lord? or who was his
            counselor?                            --Wyclif (Rom.
                                                  xi. 34).
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            A prince most prudent, of an excellent
            And unmatched wit and judgment.       --Shak.
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            Will puts in practice what wit deviseth. --Sir J.
                                                  Davies.
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            He wants not wit the dander to decline. --Dryden.
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   2. A mental faculty, or power of the mind; -- used in this
      sense chiefly in the plural, and in certain phrases; as,
      to lose one's wits; at one's wits' end, and the like.
      "Men's wittes ben so dull." --Chaucer.
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            I will stare him out of his wits.     --Shak.
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   3. Felicitous association of objects not usually connected,
      so as to produce a pleasant surprise; also. the power of
      readily combining objects in such a manner.
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            The definition of wit is only this, that it is a
            propriety of thoughts and words; or, in other terms,
            thoughts and words elegantly adapted to the subject.
                                                  --Dryden.
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            Wit which discovers partial likeness hidden in
            general diversity.                    --Coleridge.
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            Wit lying most in the assemblage of ideas, and
            putting those together with quickness and variety
            wherein can be found any resemblance or congruity,
            thereby to make up pleasant pictures in the fancy.
                                                  --Locke.
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   4. A person of eminent sense or knowledge; a man of genius,
      fancy, or humor; one distinguished for bright or amusing
      sayings, for repartee, and the like.
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            In Athens, where books and wits were ever busier
            than in any other part of Greece, I find but only
            two sorts of writings which the magistrate cared to
            take notice of; those either blasphemous and
            atheistical, or libelous.             --Milton.
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            Intemperate wits will spare neither friend nor foe.
                                                  --L'Estrange.
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            A wit herself, Amelia weds a wit.     --Young.
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   The five wits, the five senses; also, sometimes, the five
      qualities or faculties, common wit, imagination, fantasy,
      estimation, and memory. --Chaucer. Nares.
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            But my five wits nor my five senses can
            Dissuade one foolish heart from serving thee.
                                                  --Shak.
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   Syn: Ingenuity; humor; satire; sarcasm; irony; burlesque.

   Usage: Wit, Humor. Wit primarily meant mind; and now
          denotes the power of seizing on some thought or
          occurrence, and, by a sudden turn, presenting it under
          aspects wholly new and unexpected -- apparently
          natural and admissible, if not perfectly just, and
          bearing on the subject, or the parties concerned, with
          a laughable keenness and force. "What I want," said a
          pompous orator, aiming at his antagonist, "is common
          sense." "Exactly!" was the whispered reply. The
          pleasure we find in wit arises from the ingenuity of
          the turn, the sudden surprise it brings, and the
          patness of its application to the case, in the new and
          ludicrous relations thus flashed upon the view. Humor
          is a quality more congenial to the English mind than
          wit. It consists primarily in taking up the
          peculiarities of a humorist (or eccentric person) and
          drawing them out, as Addison did those of Sir Roger de
          Coverley, so that we enjoy a hearty, good-natured
          laugh at his unconscious manifestation of whims and
          oddities. From this original sense the term has been
          widened to embrace other sources of kindly mirth of
          the same general character. In a well-known caricature
          of English reserve, an Oxford student is represented
          as standing on the brink of a river, greatly agitated
          at the sight of a drowning man before him, and crying
          out, "O that I had been introduced to this gentleman,
          that I might save his life!" The "Silent Woman" of Ben
          Jonson is one of the most humorous productions, in the
          original sense of the term, which we have in our
          language.
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WordNet (r) 3.0 (2006):

wit
    n 1: a message whose ingenuity or verbal skill or incongruity
         has the power to evoke laughter [syn: wit, humor,
         humour, witticism, wittiness]
    2: mental ability; "he's got plenty of brains but no common
       sense" [syn: brain, brainpower, learning ability,
       mental capacity, mentality, wit]
    3: a witty amusing person who makes jokes [syn: wag, wit,
       card]

Moby Thesaurus II by Grady Ward, 1.0:

208 Moby Thesaurus words for "wit":
   ESP, IQ, Italian hand, ability, acumen, acuteness, address,
   adeptness, adroitness, airmanship, alertness, apprehension, art,
   artfulness, artifice, artisanship, artistry, assume, astuteness,
   awareness, balance, banana, brain, brains, bravura, brilliance,
   burlesquer, cageyness, caliber, callidity, canniness, capability,
   capacity, caricaturist, clairvoyance, cleverness, clown, comedian,
   comic, command, competence, comprehension, conceit, conceive,
   conception, control, coordination, craft, craftiness,
   craftsmanship, cunning, cunningness, cutup, deductive power,
   deftness, dexterity, dexterousness, dextrousness, diplomacy,
   discernment, discrimination, divination, droll, efficiency,
   epigrammatist, esemplastic power, esprit, expertise, facility,
   fine Italian hand, finesse, foxiness, funnyman, gag writer, gagman,
   gagster, gamesmanship, gather, grace, grasp, gray matter, grip,
   guile, handiness, head, horsemanship, humor, humorist, ideation,
   imagine, ingeniousness, ingenuity, insidiousness, insight,
   integrative power, intellect, intellectual grasp,
   intellectual power, intellectualism, intellectuality, intelligence,
   intelligence quotient, inventiveness, ironist, jester, joker,
   jokesmith, jokester, keenness, know-how, knowledge, lampooner,
   lucidity, madcap, marbles, marksmanship, mastership, mastery,
   mental age, mental capacity, mental grasp, mental ratio, mentality,
   mind, mother wit, native wit, one-upmanship, parodist, penetration,
   perception, percipience, perspicacity, power of mind,
   practical ability, prankster, proficiency, prowess, prudence,
   punner, punster, quick-wittedness, quickness, quipster,
   rationality, readiness, reason, reasoning power, reckon,
   reparteeist, resource, resourcefulness, sagaciousness, sagacity,
   sageness, saneness, sanity, sapience, satanic cunning, satirist,
   savoir-faire, savvy, scope of mind, seamanship, sense, senses,
   sensing, sharpness, shiftiness, shrewdness, skill, skillfulness,
   slipperiness, slyness, smartness, sneakiness, sophistry, stealth,
   stealthiness, style, subtilty, subtleness, subtlety, suppleness,
   suppose, tact, tactfulness, technical brilliance,
   technical mastery, technical skill, technique, think,
   thinking power, timing, trickiness, understanding, virtuosity, wag,
   wagwit, wariness, wiles, wiliness, wisdom, wisecracker,
   witlessness, witling, wizardry, workmanship, zany



The Devil's Dictionary (1881-1906):

WIT, n.  The salt with which the American humorist spoils his
intellectual cookery by leaving it out.