The Collaborative International Dictionary of English v.0.48:

Draught \Draught\, a.
   1. Used for drawing vehicles, loads, etc.; as, a draught
      beast; draught hooks.
      [1913 Webster]

   2. Relating to, or characterized by, a draft, or current of
      air.
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   3. Used in making drawings; as, draught compasses.
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   4. Drawn directly from the barrel, or other receptacle, in
      distinction from bottled; on draught; -- said of ale,
      cider, and the like.
      [1913 Webster]

   Note: This word, especially in the first and second meanings,
         is often written draft, a spelling which is approved by
         many authorities.
         [1913 Webster]

   Draught box. See Draught tube, below.

   Draught engine (Mining), an engine used for pumping,
      raising heavy weights, and the like.

   Draught hook (Mil.), one of the hooks on a cannon carriage,
      used in drawing the gun backward and forward.

   Draught horse, a horse employed in drawing loads, plowing,
      etc., as distinguished from a saddle horse or carriage
      horse.

   Draught net, a seine or hauling net.

   Draught ox, an ox employed in hauling loads, plowing, etc.


   Draught tube (Water Wheels), an air-tight pipe extending
      downward into the tailrace from a turbine wheel located
      above it, to make the whole fall available; -- called also
      draught box.
      [1913 Webster]

WordNet (r) 3.0 (2006):

draught horse
    n 1: horse adapted for drawing heavy loads [syn: draft horse,
         draught horse, dray horse]