The Collaborative International Dictionary of English v.0.48:

Commandment \Com*mand"ment\, n. [OF. commandement, F.
   commandement.]
   1. An order or injunction given by authority; a command; a
      charge; a precept; a mandate.
      [1913 Webster]

            A new commandment I give unto you, that ye love one
            another.                              --John xiii.
                                                  34.
      [1913 Webster]

   2. (Script.) One of the ten laws or precepts given by God to
      the Israelites at Mount Sinai.
      [1913 Webster]

   3. The act of commanding; exercise of authority.
      [1913 Webster]

            And therefore put I on the countenance
            Of stern commandment.                 --Shak.
      [1913 Webster]

   4. (Law) The offense of commanding or inducing another to
      violate the law.
      [1913 Webster]

   The Commandments, The Ten Commandments, the Decalogue, or
      summary of God's commands, given to Moses at Mount Sinai.
      (--Ex. xx.)
      [1913 Webster]

WordNet (r) 3.0 (2006):

commandment
    n 1: something that is commanded
    2: a doctrine that is taught; "the teachings of religion"; "he
       believed all the Christian precepts" [syn: teaching,
       precept, commandment]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "commandment":
   behest, bidding, canon, code, command, convention, dictate,
   dictation, dictum, direct order, form, formula, general principle,
   golden rule, guideline, guiding principle, hest, imperative, law,
   maxim, mitzvah, moral, norm, order, ordinance, pleasure,
   principium, principle, regulation, rubric, rule, say-so,
   settled principle, special order, standard, tenet, will, word,
   word of command, working principle, working rule