Source : Webster's Revised Unabridged Dictionary (1913)

Traffic \Traf"fic\, v. i. [imp. & p. p. {Trafficked}; p. pr. &
   vb. n. {Trafficking}.] [F. trafiquer; cf. It. trafficare, Sp.
   traficar, trafagar, Pg. traficar, trafegar, trafeguear, LL.
   traficare; of uncertain origin, perhaps fr. L. trans across,
   over + -ficare to make (see {-fy}, and cf. G. ["u]bermachen
   to transmit, send over, e. g., money, wares); or cf. Pg.
   trasfegar to pour out from one vessel into another, OPg.
   also, to traffic, perhaps fr. (assumed) LL. vicare to
   exchange, from L. vicis change (cf. {Vicar}).]
   1. To pass goods and commodities from one person to another
      for an equivalent in goods or money; to buy or sell goods;
      to barter; to trade.

   2. To trade meanly or mercenarily; to bargain.

Source : WordNet®

traffic
     n 1: the aggregation of things (pedestrians or vehicles) coming
          and going in a particular locality during a specified
          period of time
     2: buying and selling; especially illicit trade
     3: the amount of activity over a communication system during a
        given period of time; "heavy traffic overloaded the trunk
        lines"; "traffic on the internet is lightest during the
        night"
     4: social or verbal interchange (usually followed by `with')
        [syn: {dealings}]
     [also: {trafficking}, {trafficked}]

traffic
     v 1: deal illegally; "traffic drugs"
     2: trade or deal a commodity; "They trafficked with us for
        gold"
     [also: {trafficking}, {trafficked}]

trafficking
     See {traffic}