The Collaborative International Dictionary of English v.0.48:

Dictate \Dic"tate\, n. [L. dictatum. See Dictate, v. t.]
   A statement delivered with authority; an order; a command; an
   authoritative rule, principle, or maxim; a prescription; as,
   listen to the dictates of your conscience; the dictates of
   the gospel.
   [1913 Webster]

         I credit what the Grecian dictates say.  --Prior.

   Syn: Command; injunction; direction suggestion; impulse;
        admonition.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dictate \Dic"tate\, v. t. [imp. & p. p. Dictated; p. pr. & vb.
   n. Dictating.] [L. dictatus, p. p. of dictare, freq. of
   dicere to say. See Diction, and cf. Dight.]
   1. To tell or utter so that another may write down; to
      inspire; to compose; as, to dictate a letter to an
      amanuensis.
      [1913 Webster]

            The mind which dictated the Iliad.    --Wayland.
      [1913 Webster]

            Pages dictated by the Holy Spirit.    --Macaulay.
      [1913 Webster]

   2. To say; to utter; to communicate authoritatively; to
      deliver (a command) to a subordinate; to declare with
      authority; to impose; as, to dictate the terms of a
      treaty; a general dictates orders to his troops.
      [1913 Webster]

            Whatsoever is dictated to us by God must be
            believed.                             --Watts.

   Syn: To suggest; prescribe; enjoin; command; point out; urge;
        admonish.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dictate \Dic"tate\, v. i.
   1. To speak as a superior; to command; to impose conditions
      (on).
      [1913 Webster]

            Who presumed to dictate to the sovereign.
                                                  --Macaulay.
      [1913 Webster]

   2. To compose literary works; to tell what shall be written
      or said by another.
      [1913 Webster]

            Sylla could not skill of letters, and therefore knew
            not how to dictate.                   --Bacon.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dictate
    n 1: an authoritative rule
    2: a guiding principle; "the dictates of reason"
    v 1: issue commands or orders for [syn: order, prescribe,
         dictate]
    2: say out loud for the purpose of recording; "He dictated a
       report to his secretary"
    3: rule as a dictator

Moby Thesaurus II by Grady Ward, 1.0:

165 Moby Thesaurus words for "dictate":
   a priori truth, act, adage, ana, analects, aphorism, apothegm,
   appoint, authorize, axiom, behest, bestride, bid, bidding, bill,
   brocard, brook no denial, bylaw, byword, call for, call on,
   call the signals, call upon, canon, catchword, caveat, charge,
   collected sayings, command, commandment, commission, compel,
   constrain, control, current saying, declare, decree, demand,
   dictation, dictum, direct, direct order, direction, distich,
   dominate, edict, enactment, enjoin, epigram, exact, expression,
   fiat, form, formality, formula, formulary, give an order,
   give the word, gnome, golden rule, golden saying, govern, guide,
   have the ascendancy, hest, imperative, impose, injunction,
   insist upon, institution, instruct, instruction, issue a command,
   issue a writ, jus, law, lay down, lead, leave no option,
   legislation, lex, make obligatory, manage, mandate, master, maxim,
   measure, moral, mot, motto, necessitate, oblige, oracle, ordain,
   order, order about, ordinance, ordonnance, phrase, pithy saying,
   play first fiddle, pleasure, postulate, precept, predominate,
   preponderate, prescribe, prescript, prescription, prevail,
   principium, principle, proclaim, promulgate, pronounce,
   pronouncement, proposition, proverb, proverbial saying, proverbs,
   regulation, require, requirement, rubric, rule, rule the roost,
   ruling, saw, say, say the word, say-so, saying, self-evident truth,
   sentence, sententious expression, set, settled principle, sloka,
   special order, standing order, statute, stock saying, sutra,
   take no denial, take the lead, teaching, tell, text, theorem,
   truism, truth, twist, ukase, universal truth, utter, verse,
   wear the pants, will, wisdom, wisdom literature, wise saying,
   witticism, word, word of command, words of wisdom