Source : Webster's Revised Unabridged Dictionary (1913)

Truck \Truck\, n. [Cf. F. troc.]
   1. Exchange of commodities; barter. --Hakluyt.

   2. Commodities appropriate for barter, or for small trade;
      small commodities; esp., in the United States, garden
      vegetables raised for the market. [Colloq.]

   3. The practice of paying wages in goods instead of money; --
      called also {truck system}.

   {Garden truck}, vegetables raised for market. [Colloq.] [U.
      S.]

   {Truck farming}, raising vegetables for market: market
      gardening. [Colloq. U. S.]

Source : WordNet®

truck farming
     n : growing vegetables for the market