Source : Webster's Revised Unabridged Dictionary (1913)

Trader \Trad"er\, n.
   1. One engaged in trade or commerce; one who makes a business
      of buying and selling or of barter; a merchant; a
      trafficker; as, a trader to the East Indies; a country
      trader.

   2. A vessel engaged in the coasting or foreign trade.

Source : WordNet®

trader
     n : someone who purchases and maintains an inventory of goods to
         be sold [syn: {bargainer}, {dealer}, {monger}]