The Collaborative International Dictionary of English v.0.48:

Reveal \Re*veal"\, v. t. [imp. & p. p. Revealed; p. pr. & vb.
   n. Revealing.] [F. r['e]v['e]ler, L. revelare, revelatum,
   to unveil, reveal; pref. re- re- + velare to veil; fr. velum
   a veil. See Veil.]
   1. To make known (that which has been concealed or kept
      secret); to unveil; to disclose; to show.
      [1913 Webster]

            Light was the wound, the prince's care unknown,
            She might not, would not, yet reveal her own.
                                                  --Waller.
      [1913 Webster]

   2. Specifically, to communicate (that which could not be
      known or discovered without divine or supernatural
      instruction or agency).
      [1913 Webster]

   Syn: To communicate; disclose; divulge; unveil; uncover;
        open; discover; impart; show.

   Usage: See Communicate. -- Reveal, Divulge. To reveal
          is literally to lift the veil, and thus make known
          what was previously concealed; to divulge is to
          scatter abroad among the people, or make publicly
          known. A mystery or hidden doctrine may be revealed;
          something long confined to the knowledge of a few is
          at length divulged. "Time, which reveals all things,
          is itself not to be discovered." --Locke. "A tragic
          history of facts divulged." --Wordsworth.
          [1913 Webster]

WordNet (r) 3.0 (2006):

revealing
    adj 1: disclosing unintentionally; "a telling smile"; "a
           telltale panel of lights"; "a telltale patch of oil on
           the water marked where the boat went down" [syn:
           revealing, telling, telltale(a)]
    2: showing or making known; "her dress was scanty and revealing"
       [ant: concealing]
    n 1: the speech act of making something evident [syn:
         disclosure, revelation, revealing]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "revealing":
   apocalypse, apocalyptic, baring, betraying, clear,
   clear as crystal, crystal, crystal-clear, crystalline, diaphane,
   diaphanous, disclosing, disclosive, disclosure, discovering,
   discovery, expose, exposing, exposition, exposure, eye-opening,
   filmy, gauzy, gossamer, gossamery, laying bare, light-pervious,
   limpid, lucid, manifestation, nonopaque, patefaction, peekaboo,
   pellucid, removing the veil, revealment, revelation, revelational,
   revelatory, see-through, sheer, showing, showing up, showup,
   stripping, talkative, thin, transparent, transpicuous, uncloaking,
   unclouded, uncovering, unfolding, unfoldment, unmasking, unveiling,
   unwrapping