The Collaborative International Dictionary of English v.0.48:

Sophisticate \So*phis"ti*cate\, v. t. [imp. & p. p.
   Sophisticated; p. pr. & vb. n. Sophisticating.] [LL.
   sophisticatus, p. p. of sophisticare to sophisticate.]
   To render worthless by admixture; to adulterate; to damage;
   to pervert; as, to sophisticate wine. --Howell.
   [1913 Webster]

         To sophisticate the understanding.       --Southey.
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         Yet Butler professes to stick to plain facts, not to
         sophisticate, not to refine.             --M. Arnold.
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         They purchase but sophisticated ware.    --Dryden.
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   Syn: To adulterate; debase; corrupt; vitiate.
        [1913 Webster] Sophisticate

The Collaborative International Dictionary of English v.0.48:

Sophisticate \So*phis"ti*cate\, Sophisticated
\So*phis"ti*ca`ted\, a.
   Adulterated; not pure; not genuine.
   [1913 Webster]

         So truth, while only one supplied the state,
         Grew scare and dear, and yet sophisticate. --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sophisticate
    n 1: a worldly-wise person [syn: sophisticate, man of the
         world]
    v 1: make less natural or innocent; "Their manners had
         sophisticated the young girls"
    2: practice sophistry; change the meaning of or be vague about
       in order to mislead or deceive; "Don't twist my words" [syn:
       twist, twist around, pervert, convolute,
       sophisticate]
    3: alter and make impure, as with the intention to deceive;
       "Sophisticate rose water with geraniol" [syn: sophisticate,
       doctor, doctor up]
    4: make more complex or refined; "a sophisticated design"

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "sophisticate":
   blase, city slicker, cosmopolitan, cosmopolite, debase,
   disenchanted, disillusioned, doctor, knowing, load,
   man of experience, man-about-town, mondaine, slicker, weight,
   world-wise, worldly, worldly-wise