The Collaborative International Dictionary of English v.0.48:

Curiosity \Cu`ri*os"i*ty\ (k[=u]`r[i^]*[o^]s"[i^]*t[y^]), n.;
   pl. Curiosities (-t[i^]z). [OE. curiouste, curiosite, OF.
   curioset['e], curiosit['e], F. curiosit['e], fr. L.
   curiositas, fr. curiosus. See Curious, and cf. Curio.]
   1. The state or quality or being curious; nicety; accuracy;
      exactness; elaboration. [Obs.] --Bacon.
      [1913 Webster]

            When thou wast in thy gilt and thy perfume, they
            mocked thee for too much curiosity.   --Shak.
      [1913 Webster]

            A screen accurately cut in tapiary work . . . with
            great curiosity.                      --Evelin.
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   2. Disposition to inquire, investigate, or seek after
      knowledge; a desire to gratify the mind with new
      information or objects of interest; inquisitiveness.
      --Milton.
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   3. That which is curious, or fitted to excite or reward
      attention.
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            We took a ramble together to see the curiosities of
            this great town.                      --Addison.
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            There hath been practiced also a curiosity, to set a
            tree upon the north side of a wall, and, at a little
            hieght, to draw it through the wall, etc. --Bacon.
      [1913 Webster]

WordNet (r) 3.0 (2006):

curiosity
    n 1: a state in which you want to learn more about something
         [syn: curiosity, wonder]
    2: something unusual -- perhaps worthy of collecting [syn:
       curio, curiosity, oddity, oddment, peculiarity,
       rarity]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "curiosity":
   abnormality, amazement, anomaly, ardor, astonishing thing,
   astonishment, bauble, bric-a-brac, cathexis, concern, concernment,
   concupiscence, conversation piece, curio, desideration, desire,
   drive, eagerness, enthusiasm, exception, fancy, fantasy, freak,
   gazingstock, gewgaw, hope, horme, improbability, inquisitiveness,
   intellectual curiosity, interest, interestedness, interference,
   intrusiveness, libido, lust for learning, marvel, marvelment,
   matter of interest, meddlesomeness, mind, miracle, monstrosity,
   museum piece, need, nonesuch, nosiness, objet d'art, oddity,
   passion, phenomenon, pleasure, pleasure principle, prodigiosity,
   prodigy, prying, questioning, quite a thing, rarity, regard,
   sensation, sexual desire, sight, snooping, something else,
   special interest, spectacle, strange thing, stunner,
   thirst for knowledge, trinket, urge, want, wanting, will,
   will and pleasure, wish, wish fulfillment, wonder, wonderful thing,
   wonderment



The Devil's Dictionary (1881-1906):

CURIOSITY, n.  An objectionable quality of the female mind.  The
desire to know whether or not a woman is cursed with curiosity is one
of the most active and insatiable passions of the masculine soul.