The Collaborative International Dictionary of English v.0.48:

Pretense \Pre*tense"\, Pretence \Pre*tence\, n. [LL. praetensus,
   for L. praetentus, p. p. of praetendere. See Pretend, and
   cf. Tension.]
   1. The act of laying claim; the claim laid; assumption;
      pretension. --Spenser.
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            Primogeniture can not have any pretense to a right
            of solely inheriting property or power. --Locke.
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            I went to Lambeth with Sir R. Brown's pretense to
            the wardenship of Merton College, Oxford. --Evelyn.
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   2. The act of holding out, or offering, to others something
      false or feigned; presentation of what is deceptive or
      hypocritical; deception by showing what is unreal and
      concealing what is real; false show; simulation; as,
      pretense of illness; under pretense of patriotism; on
      pretense of revenging C[ae]sar's death.
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   3. That which is pretended; false, deceptive, or hypocritical
      show, argument, or reason; pretext; feint.
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            Let not the Trojans, with a feigned pretense
            Of proffered peace, delude the Latian prince.
                                                  --Dryden.
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   4. Intention; design. [Obs.]
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            A very pretense and purpose of unkindness. --Shak.
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   Note: See the Note under Offense.
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   Syn: Mask; appearance; color; show; pretext; excuse.

   Usage: Pretense, Pretext. A pretense is something held
          out as real when it is not so, thus falsifying the
          truth. A pretext is something woven up in order to
          cover or conceal one's true motives, feelings, or
          reasons. Pretext is often, but not always, used in a
          bad sense.
          [1913 Webster]

WordNet (r) 3.0 (2006):

pretense
    n 1: the act of giving a false appearance; "his conformity was
         only pretending" [syn: pretense, pretence,
         pretending, simulation, feigning]
    2: pretending with intention to deceive [syn: pretense,
       pretence, feigning, dissembling]
    3: imaginative intellectual play [syn: pretense, pretence,
       make-believe]
    4: a false or unsupportable quality [syn: pretension,
       pretense, pretence]
    5: an artful or simulated semblance; "under the guise of
       friendship he betrayed them" [syn: guise, pretense,
       pretence, pretext]

Moby Thesaurus II by Grady Ward, 1.0:

143 Moby Thesaurus words for "pretense":
   acting, affectation, affectedness, air, airs, airs and graces,
   alibi, apology, appearance, appurtenance, artificiality,
   attitudinizing, authority, birthright, blind, bluff, bluffing,
   charade, cheating, claim, cloak, color, coloring, conjugal right,
   cover, cover story, cover-up, deceit, deception, delusion, demand,
   device, disguise, dissemblance, dissembling, dissimulation,
   divine right, droit, due, excuse, explanation, facade, face,
   faculty, fake, fakery, faking, false air, false front, false show,
   falsity, feigned belief, feigning, feint, four-flushing, fraud,
   front, gilt, gloss, guise, handle, humbug, humbuggery, hypocrisy,
   image, imposture, inalienable right, insincerity, interest,
   lame excuse, locus standi, loftiness, lofty affectations,
   make-believe, mannerism, mask, masquerade, mere show,
   meretriciousness, natural right, ostensible motive, ostent,
   ostentation, ostentatiousness, outward show, pageant, playacting,
   poor excuse, pose, posing, posture, power, prerogative,
   prescription, presumptive right, pretension, pretentiousness,
   pretext, proper claim, property right, protestation,
   prunes and prisms, public image, public motive, put-off, put-on,
   putting on airs, rational ground, rationale, reason, reason for,
   reason why, refuge, representation, right, screen, seeming,
   semblance, sham, show, simulacrum, simulation, smoke screen,
   speciousness, stalking-horse, stated cause, stratagem, stylishness,
   subterfuge, the big idea, the idea, the whatfor, the wherefore,
   the why, title, trick, underlying reason, unnaturalness, varnish,
   veil, vested interest, vested right, window dressing