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.
      [1913 Webster]

            We are more heavily taxed by our idleness, pride,
            and folly than we are taxed by government.
                                                  --Franklin.
      [1913 Webster]

   2. (Law) To assess, fix, or determine judicially, the amount
      of; as, to tax the cost of an action in court.
      [1913 Webster]

   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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WordNet (r) 3.0 (2006):

taxing
    adj 1: not easily borne; wearing; "the burdensome task of
           preparing the income tax return"; "my duties weren't
           onerous; I only had to greet the guests"; "a taxing
           schedule" [syn: burdensome, onerous, taxing]

Moby Thesaurus II by Grady Ward, 1.0:

146 Moby Thesaurus words for "taxing":
   accusal, accusation, accusing, allegation, allegement, arraignment,
   bale, bill of particulars, blackmail, blame, bother,
   bringing of charges, bringing to book, burden, burdening,
   burdensome, burthen, call, call for, cargo, charge, charging,
   claim, clamant, clamorous, complaint, contribution, count, crying,
   cumber, cumbrance, deadweight, delation, demand, demand for,
   demanding, denouncement, denunciation, draft, drag, drain,
   draining, duty, encumbrance, exacting, exaction, exigent,
   exorbitant, extortion, extortionate, extortionate demand, freight,
   freighting, grasping, grievous, handicap, haul, heave,
   heavy demand, impeachment, implication, importunate,
   imposing an onus, imposition, impost, imputation,
   inconsiderateness, inconvenience, incubus, incumbency, indent,
   indictment, infliction, information, innuendo, insinuation,
   insistent, insistent demand, instant, lading, lawsuit,
   laying of charges, laying on, levy, load, loading, loading down,
   loud, millstone, nonnegotiable demand, notice, obtrusiveness,
   oppression, oppressive, order, overexertion, overextension,
   overload, overstrain, overstress, overtaxing, overweighting,
   persistent, pertinacious, plaint, pressing, pressure,
   presumptuousness, prosecution, pull, rack, reproach, requirement,
   requisition, rush, rush order, saddling, strain, straining, stress,
   stress and strain, stressfulness, stretch, suit, superincumbency,
   surcharge, tasking, tax, tedious, tension, tough, tribute, trouble,
   troublesome, true bill, trying, tug, ultimatum,
   unspoken accusation, unwarranted demand, urgent, veiled accusation,
   warning, wearing, weighting, weighty



Easton's 1897 Bible Dictionary:

Taxing
   (Luke 2:2; R.V., "enrolment"), "when Cyrenius was governor of
   Syria," is simply a census of the people, or an enrolment of
   them with a view to their taxation. The decree for the enrolment
   was the occasion of Joseph and Mary's going up to Bethlehem. It
   has been argued by some that Cyrenius (q.v.) was governor of
   Cilicia and Syria both at the time of our Lord's birth and some
   years afterwards. This decree for the taxing referred to the
   whole Roman world, and not to Judea alone. (See CENSUS.)