The Collaborative International Dictionary of English v.0.48:

Conspicuous \Con*spic"u*ous\, a. [L. conspicuus, fr. conspicere
   to get sight of, to perceive; con- + spicere, specere, to
   look. See Spy]
   1. Open to the view; obvious to the eye; easy to be seen;
      plainly visible; manifest; attracting the eye.
      [1913 Webster]

            It was a rock
            Of alabaster, piled up to the clouds,
            Conspicious far.                      --Milton.
      [1913 Webster]

            Conspicious by her veil and hood,
            Signing the cross, the abbess stood.  --Sir W.
                                                  Scott.
      [1913 Webster]

   2. Obvious to the mental eye; easily recognized; clearly
      defined; notable; prominent; eminent; distinguished; as, a
      conspicuous excellence, or fault.
      [1913 Webster]

            A man who holds a conspicuous place in the
            political, ecclesiastical, and literary history of
            England.                              --Macaulay.

   Syn: Distinguished; eminent; famous; illustrious; prominent;
        celebrated. See Distinguished. -- Con*spic"u*ous*ly,
        adv. -- Con*spic"u*ous*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

conspicuous
    adj 1: obvious to the eye or mind; "a tower conspicuous at a
           great distance"; "wore conspicuous neckties"; "made
           herself conspicuous by her exhibitionistic preening"
           [ant: inconspicuous, invisible]
    2: without any attempt at concealment; completely obvious;
       "blatant disregard of the law"; "a blatant appeal to vanity";
       "a blazing indiscretion" [syn: blatant, blazing,
       conspicuous]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "conspicuous":
   appalling, apparent, arrant, arresting, astonishing, awe-inspiring,
   awesome, blatant, bold, celebrated, clean-cut, clear,
   clear as crystal, clear-cut, consequential, crystal-clear, defined,
   definite, distinct, distinguished, egregious, eminent, esteemed,
   estimable, evident, exceptional, extraordinary, fabulous,
   fantastic, flagrant, flashy, formidable, garish, gaudy, glaring,
   glorious, hanging out, illustrious, important, impressive,
   in focus, in relief, in the foreground, in the limelight,
   incontestable, incontrovertible, incredible, loud, lurid, manifest,
   marked, marvelous, memorable, noble, notable, noteworthy,
   noticeable, notorious, obtrusive, obvious, of mark, open-and-shut,
   openhanded, ostensible, ostentatious, outstanding, palpable,
   patent, perceptible, plain, pointed, prestigious, prominent,
   pronounced, rare, remarkable, rememberable, reputable, salient,
   showy, signal, significant, special, staring, stark-staring,
   sticking out, striking, superior, tawdry, telling, to the front,
   uncommon, unforgettable, unmistakable, unquestionable, unusual,
   vivid, vulgar, well-defined, well-marked, well-pronounced,
   well-resolved, wonderful