The Collaborative International Dictionary of English v.0.48:

Promulgate \Pro*mul"gate\, v. t. [imp. & p. p. Promulgated; p.
   pr. & vb. n. Promulgating.] [L. promulgatus, p. p. of
   promulgare to promulgate; of unknown origin. Cf. Promulge.]
   To make known by open declaration, as laws, decrees, or
   tidings; to publish; as, to promulgate the secrets of a
   council.
   [1913 Webster]

   Syn: To publish; declare; proclaim. 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):

promulgate
    v 1: state or announce; "`I am not a Communist,' he exclaimed";
         "The King will proclaim an amnesty" [syn: proclaim,
         exclaim, promulgate]
    2: put a law into effect by formal declaration