The Collaborative International Dictionary of English v.0.48:

Obfuscate \Ob*fus"cate\, a. [L. obfuscatus, p. p. of obfuscare
   to darken; ob (see Ob-) + fuscare, fuscatum, to darken,
   from fuscus dark.]
   Obfuscated; darkened; obscured. [Obs.] [Written also
   offuscate.] --Sir. T. Elyot.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Obfuscate \Ob*fus"cate\, v. t. [imp. & p. p. Obfuscated; p.
   pr. & vb. n. Obfuscating.]
   1. To darken; to obscure; to becloud.
      [1913 Webster]

   2. Hence: To confuse; to bewilder; to make unclear.
      [1913 Webster]

            His head, like a smokejack, the funnel unswept, and
            the ideas whirling round and round about in it, all
            obfuscated and darkened over with fuliginous matter.
                                                  --Sterne.
      [1913 Webster]

            Clouds of passion which might obfuscate the
            intellects of meaner females.         --Sir. W.
                                                  Scott.
      [1913 Webster]

WordNet (r) 3.0 (2006):

obfuscate
    v 1: make obscure or unclear [ant: clarify, clear up,
         elucidate]

Moby Thesaurus II by Grady Ward, 1.0:

85 Moby Thesaurus words for "obfuscate":
   adumbrate, becloud, bedarken, bedim, befog, begloom, black,
   black out, blacken, blanket, blind, block the light, blot out,
   blur, brown, camouflage, cast a shadow, cloak, cloud, cloud over,
   complicate, conceal, confuse, corrupt, cover, cover up, curtain,
   darken, darken over, deform, dim, dim out, disguise, disorder,
   dissemble, distort, distract attention from, eclipse, encloud,
   encompass with shadow, ensconce, enshroud, envelop, fog up, garble,
   gloom, gloss over, hide, jumble, keep under cover,
   make unintelligible, mask, mess up, misadvise, misdirect,
   miseducate, misguide, misinform, misinstruct, mislead, misteach,
   muddle, murk, mystify, obnubilate, obscure, obumbrate, occult,
   occultate, overcast, overcloud, overshadow, pervert, scramble,
   screen, shade, shadow, shroud, slur over, somber, unform, unshape,
   varnish, veil, whitewash