The Collaborative International Dictionary of English v.0.48:

Indirect \In`di*rect"\, a. [Pref. in- not + direct: cf. F.
   indirect.]
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   1. Not direct; not straight or rectilinear; deviating from a
      direct line or course; circuitous; as, an indirect road.
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   2. Not tending to an aim, purpose, or result by the plainest
      course, or by obvious means, but obliquely or
      consequentially; by remote means; as, an indirect
      accusation, attack, answer, or proposal.
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            By what bypaths and indirect, crooked ways
            I met this crown.                     --Shak.
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   3. Not straightforward or upright; unfair; dishonest; tending
      to mislead or deceive.
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            Indirect dealing will be discovered one time or
            other.                                --Tillotson.
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   4. Not resulting directly from an act or cause, but more or
      less remotely connected with or growing out of it; as,
      indirect results, damages, or claims.
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   5. (Logic & Math.) Not reaching the end aimed at by the most
      plain and direct method; as, an indirect proof,
      demonstration, etc.
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   Indirect claims, claims for remote or consequential damage.
      Such claims were presented to and thrown out by the
      commissioners who arbitrated the damage inflicted on the
      United States by the Confederate States cruisers built and
      supplied by Great Britain.

   Indirect demonstration, a mode of demonstration in which
      proof is given by showing that any other supposition
      involves an absurdity (reductio ad absurdum), or an
      impossibility; thus, one quantity may be proved equal to
      another by showing that it can be neither greater nor
      less.

   Indirect discourse. (Gram.) See Direct discourse, under
      Direct.

   Indirect evidence, evidence or testimony which is
      circumstantial or inferential, but without witness; --
      opposed to direct evidence.

   Indirect tax, a tax, such as customs, excises, etc.,
      exacted directly from the merchant, but paid indirectly by
      the consumer in the higher price demanded for the articles
      of merchandise.
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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):

indirect
    adj 1: having intervening factors or persons or influences;
           "reflection from the ceiling provided a soft indirect
           light"; "indirect evidence"; "an indirect cause"
    2: not direct in spatial dimension; not leading by a straight
       line or course to a destination; "sometimes taking an
       indirect path saves time"; "you must take an indirect course
       in sailing" [ant: direct]
    3: descended from a common ancestor but through different lines;
       "cousins are collateral relatives"; "an indirect descendant
       of the Stuarts" [syn: collateral, indirect] [ant:
       direct, lineal]
    4: extended senses; not direct in manner or language or behavior
       or action; "making indirect but legitimate inquiries"; "an
       indirect insult"; "doubtless they had some indirect purpose
       in mind"; "though his methods are indirect they are not
       dishonest"; "known as a shady indirect fellow" [ant:
       direct]
    5: not as a direct effect or consequence; "indirect benefits";
       "an indirect advantage"

Moby Thesaurus II by Grady Ward, 1.0:

142 Moby Thesaurus words for "indirect":
   O-shaped, aberrant, aberrative, accessory, accidental, additional,
   adscititious, adventitious, ambagious, amoral, ancillary, artful,
   backhand, backhanded, calculating, chiseling, circuitous, circular,
   circumambient, circumlocutional, circumlocutory, collateral,
   collusive, coming, conscienceless, contingent, corrupt, corrupted,
   covinous, crafty, criminal, crooked, cunning, dark, deceitful,
   deflectional, departing, desultory, deviant, deviating, deviative,
   deviatory, devious, digressive, discursive, dishonest,
   dishonorable, divagational, divergent, doubtful, dubious,
   duplicitous, errant, erratic, evasive, eventual, excursive, false,
   falsehearted, felonious, finagling, final, fishy, fraudulent,
   furtive, guileful, helical, ill-got, ill-gotten, immoral,
   incidental, insidious, labyrinthine, last, left-handed, mazy,
   meandering, not kosher, oblique, orbital, out-of-the-way,
   periphrastic, planetary, questionable, rambling, rotary, rotten,
   round, roundabout, roving, scheming, secondary, serpentine, shady,
   shameless, sharp, shifting, shifty, side, sidelong, sinister,
   sinistral, sinuous, slippery, snaky, sneaking, sneaky, spiral,
   stray, subordinate, subsidiary, surreptitious, suspicious,
   swerving, tortuous, treacherous, trickish, tricky, turning,
   twisted, twisting, two-faced, ultimate, unconscienced,
   unconscientious, unconscionable, underhand, underhanded,
   undirected, unethical, unprincipled, unsavory, unscrupulous,
   unstraightforward, vagrant, veering, wandering, wily, winding,
   without remorse, without shame, zigzag