Source : Webster's Revised Unabridged Dictionary (1913)

Commerce \Com"merce\, n.

   Note: (Formerly accented on the second syllable.) [F.
         commerce, L. commercium; com- + merx, mercis,
         merchandise. See {Merchant}.]
   1. The exchange or buying and selling of commodities; esp.
      the exchange of merchandise, on a large scale, between
      different places or communities; extended trade or
      traffic.

            The public becomes powerful in proportion to the
            opulence and extensive commerce of private men.
                                                  --Hume.

   2. Social intercourse; the dealings of one person or class in
      society with another; familiarity.

            Fifteen years of thought, observation, and commerce
            with the world had made him [Bunyan] wiser.
                                                  --Macaulay.

   3. Sexual intercourse. --W. Montagu.

   4. A round game at cards, in which the cards are subject to
      exchange, barter, or trade. --Hoyle.

   {Chamber of commerce}. See {Chamber}.

   Syn: Trade; traffic; dealings; intercourse; interchange;
        communion; communication.

Commerce \Com*merce"\ (? or ?), v. i. [imp. & p. p. {Commerced};
   p>. pr. & vb. n. {Commercing}.] [Cf. F. commercer, fr. LL.
   commerciare.]
   1. To carry on trade; to traffic. [Obs.]

            Beware you commerce not with bankrupts. --B. Jonson.

   2. To hold intercourse; to commune. --Milton.

            Commercing with himself.              --Tennyson.

            Musicians . . . taught the people in angelic
            harmonies to commerce with heaven.    --Prof.
                                                  Wilson.

Source : WordNet®

commerce
     n 1: transactions (sales and purchases) having the objective of
          supplying commodities (goods and services) [syn: {commercialism},
           {mercantilism}]
     2: the United States federal department that promotes and
        administers domestic and foreign trade (including
        management of the census and the patent office); created
        in 1913 [syn: {Department of Commerce}, {Commerce
        Department}, {DoC}]
     3: social exchange, especially of opinions, attitudes, etc.