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]

Moby Thesaurus II by Grady Ward, 1.0:

125 Moby Thesaurus words for "proclaim":
   advertise, affirm, allege, announce, annunciate, antecede,
   antedate, anticipate, argue, articulate, assert, assever,
   asseverate, aver, avouch, avow, be before, be early, bid, blare,
   blare forth, blaze, blaze abroad, blazon, blazon about, brand,
   broadcast, bruit about, call on, call the signals, call upon,
   celebrate, characterize, charge, circulate, come before, command,
   commission, contend, cry, cry out, declaim, declare, decree,
   demonstrate, dictate, direct, disseminate, dogmatize, enjoin,
   enunciate, evidence, evince, exhibit, express, forerun,
   give an order, give notice, give the word, go before, harbinger,
   have, herald, herald abroad, hold, illustrate, insist, instruct,
   issue a command, issue a manifesto, issue a writ, lay down,
   maintain, make known, mandate, manifest, manifesto, mark, notify,
   nuncupate, oracle, oraculate, ordain, order, order about,
   pontificate, preannounce, precede, precurse, predate, predicate,
   preexist, profess, promulgate, pronounce, protest, publish, put,
   put it, quote, recite, relate, report, rule, run before, say,
   say the word, set down, shout, speak, speak out, speak up,
   stand for, stand on, state, submit, thunder, thunder forth,
   trumpet, trumpet forth, usher in, utter, vent, ventilate, voice