Source : Webster's Revised Unabridged Dictionary (1913)

Truckman \Truck"man\, n.; pl. {Truckmen}.
   1. [From {Truck} barter.] One who does business in the way of
      barter or exchange.

   2. [From {Truck} a carriage.] One who drives a truck, or
      whose business is the conveyance of goods on trucks.