The Collaborative International Dictionary of English v.0.48:

Smart \Smart\, a. [Compar. Smarter; superl. Smartest.] [OE.
   smerte. See Smart, v. i.]
   1. Causing a smart; pungent; pricking; as, a smart stroke or
      taste.
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            How smart lash that speech doth give my conscience.
                                                  --Shak.
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   2. Keen; severe; poignant; as, smart pain.
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   3. Vigorous; sharp; severe. "Smart skirmishes, in which many
      fell." --Clarendon.
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   4. Accomplishing, or able to accomplish, results quickly;
      active; sharp; clever. [Colloq.]
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   5. Efficient; vigorous; brilliant. "The stars shine smarter."
      --Dryden.
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   6. Marked by acuteness or shrewdness; quick in suggestion or
      reply; vivacious; witty; as, a smart reply; a smart
      saying.
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            Who, for the poor renown of being smart
            Would leave a sting within a brother's heart?
                                                  --Young.
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            A sentence or two, . . . which I thought very smart.
                                                  --Addison.
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   7. Pretentious; showy; spruce; as, a smart gown.
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   8. Brisk; fresh; as, a smart breeze.
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   Smart money.
      (a) Money paid by a person to buy himself off from some
          unpleasant engagement or some painful situation.
      (b) (Mil.) Money allowed to soldiers or sailors, in the
          English service, for wounds and injures received;
          also, a sum paid by a recruit, previous to being sworn
          in, to procure his release from service.
      (c) (Law) Vindictive or exemplary damages; damages beyond
          a full compensation for the actual injury done.
          --Burrill. --Greenleaf.

   Smart ticket, a certificate given to wounded seamen,
      entitling them to smart money. [Eng.] --Brande & C.
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   Syn: Pungent; poignant; sharp; tart; acute; quick; lively;
        brisk; witty; clever; keen; dashy; showy.

   Usage: Smart, Clever. Smart has been much used in New
          England to describe a person who is intelligent,
          vigorous, and active; as, a smart young fellow; a
          smart workman, etc., conciding very nearly with the
          English sense of clever. The nearest approach to this
          in England is in such expressions as, he was smart
          (pungent or witty) in his reply, etc.; but smart and
          smartness, when applied to persons, more commonly
          refer to dress; as, a smart appearance; a smart gown,
          etc.
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WordNet (r) 3.0 (2006):

smart money
    n 1: money bet or invested by experienced gamblers or investors
         (especially if they have inside information)
    2: (law) compensation in excess of actual damages (a form of
       punishment awarded in cases of malicious or willful
       misconduct) [syn: punitive damages, exemplary damages,
       smart money]
    3: people who are highly experienced or who have inside
       information; "the smart money said Truman would lose the
       election"