The Collaborative International Dictionary of English v.0.48:

Tax \Tax\ (t[a^]ks), v. t. [imp. & p. p. Taxed; p. pr. & vb.
   n. Taxing.] [Cf. F. taxer. See Tax, n.]
   1. To subject to the payment of a tax or taxes; to impose a
      tax upon; to lay a burden upon; especially, to exact money
      from for the support of government.
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            We are more heavily taxed by our idleness, pride,
            and folly than we are taxed by government.
                                                  --Franklin.
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   2. (Law) To assess, fix, or determine judicially, the amount
      of; as, to tax the cost of an action in court.
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   3. To charge; to accuse; also, to censure; -- often followed
      by with, rarely by of before an indirect object; as, to
      tax a man with pride.
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            I tax you, you elements, with unkindness. --Shak.
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            Men's virtues I have commended as freely as I have
            taxed their crimes.                   --Dryden.
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            Fear not now that men should tax thine honor. --M.
                                                  Arnold.
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The Collaborative International Dictionary of English v.0.48:

Tax \Tax\, n. [F. taxe, fr. taxer to tax, L. taxare to touch,
   sharply, to feel, handle, to censure, value, estimate, fr.
   tangere, tactum, to touch. See Tangent, and cf. Task,
   Taste.]
   1. A charge, especially a pecuniary burden which is imposed
      by authority. Specifically:
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      (a) A charge or burden laid upon persons or property for
          the support of a government.
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                A farmer of taxes is, of all creditors,
                proverbially the most rapacious.  --Macaulay.
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      (b) Especially, the sum laid upon specific things, as upon
          polls, lands, houses, income, etc.; as, a land tax; a
          window tax; a tax on carriages, and the like.

   Note: Taxes are annual or perpetual, direct or
         indirect, etc.
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      (c) A sum imposed or levied upon the members of a society
          to defray its expenses.
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   2. A task exacted from one who is under control; a
      contribution or service, the rendering of which is imposed
      upon a subject.
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   3. A disagreeable or burdensome duty or charge; as, a heavy
      tax on time or health.
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   4. Charge; censure. [Obs.] --Clarendon.
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   5. A lesson to be learned; a task. [Obs.] --Johnson.
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   Tax cart, a spring cart subject to a low tax. [Eng.]
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   Syn: Impost; tribute; contribution; duty; toll; rate;
        assessment; exaction; custom; demand.
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WordNet (r) 3.0 (2006):

tax
    n 1: charge against a citizen's person or property or activity
         for the support of government [syn: tax, taxation,
         revenue enhancement]
    v 1: levy a tax on; "The State taxes alcohol heavily"; "Clothing
         is not taxed in our state"
    2: set or determine the amount of (a payment such as a fine)
       [syn: tax, assess]
    3: use to the limit; "you are taxing my patience" [syn: tax,
       task]
    4: make a charge against or accuse; "They taxed him failure to
       appear in court"