The Collaborative International Dictionary of English v.0.48:

Proclaim \Pro*claim"\, v. t. [imp. & p. p. Proclaimed; p. pr.
   & vb. n. Proclaiming.] [OE. proclamen, L. proclamare; pro
   before, forward + clamare to call or cry out: cf. F.
   proclamer. See Claim.]
   [1913 Webster]
   1. To make known by public announcement; to give wide
      publicity to; to publish abroad; to promulgate; to
      declare; as, to proclaim war or peace.
      [1913 Webster]

            To proclaim liberty to the captives.  --Isa. lxi. 1.
      [1913 Webster]

            For the apparel oft proclaims the man. --Shak.
      [1913 Webster]

            Throughout the host proclaim
            A solemn council forthwith to be held. --Milton.
      [1913 Webster]

   2. To outlaw by public proclamation.
      [1913 Webster]

            I heard myself proclaimed.            --Shak.
      [1913 Webster]

   Syn: To publish; promulgate; declare; announce. See
        Announce.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Announce \An*nounce"\, v. t. [imp. & p. p. Announced; p. pr. &
   vb. n. Announcing.] [OF. anoncier, F. annoncer, fr. L.
   annuntiare; ad + nuntiare to report, relate, nuntius
   messenger, bearer of news. See Nuncio, and cf.
   Annunciate.]
   [1913 Webster]
   1. To give public notice, or first notice of; to make known;
      to publish; to proclaim.
      [1913 Webster]

            Her [Q. Elizabeth's] arrival was announced through
            the country by a peal of cannon from the ramparts.
                                                  --Gilpin.
      [1913 Webster]

   2. To pronounce; to declare by judicial sentence.
      [1913 Webster]

            Publish laws, announce
            Or life or death.                     --Prior.
      [1913 Webster]

   Syn: To proclaim; publish; make known; herald; declare;
        promulgate.

   Usage: To Publish, Announce, Proclaim, Promulgate. We
          publish what we give openly to the world, either by
          oral communication or by means of the press; as, to
          publish abroad the faults of our neighbors. We
          announce what we declare by anticipation, or make
          known for the first time; as, to announce the speedy
          publication of a book; to announce the approach or
          arrival of a distinguished personage. We proclaim
          anything to which we give the widest publicity; as, to
          proclaim the news of victory. We promulgate when
          we proclaim more widely what has before been known by
          some; as, to promulgate the gospel.
          [1913 Webster]

WordNet (r) 3.0 (2006):

proclaim
    v 1: declare formally; declare someone to be something; of
         titles; "He was proclaimed King"
    2: state or announce; "`I am not a Communist,' he exclaimed";
       "The King will proclaim an amnesty" [syn: proclaim,
       exclaim, promulgate]
    3: affirm or declare as an attribute or quality of; "The speech
       predicated the fitness of the candidate to be President"
       [syn: predicate, proclaim]
    4: praise, glorify, or honor; "extol the virtues of one's
       children"; "glorify one's spouse's cooking" [syn: laud,
       extol, exalt, glorify, proclaim]