Sway bar \Sway bar\ (Vehicles)
   (a) A bar attached to the hounds, in the rear of the front axle, so as to slide on the reach as the axle is swung in turning the vehicle.
   (b) Either of the two bars used in coupling the front and rear sleds of a logging sled; also, the bar used to couple two logging cars.

Source: Webster's Revised Unabridged Dictionary (1913)