Muz·zle n.
  1. The projecting mouth and nose of a quadruped, as of a horse; a snout.
  2. The mouth of a thing; the end for entrance or discharge; as, the muzzle of a gun.
  3. A fastening or covering (as a band or cage) for the mouth of an animal, to prevent eating or vicious biting.
     With golden muzzles all their mouths were bound   --Dryden.
  Muzzle sight. Gun. See Dispart, n., 2.
  Dis·part, n.
  1. Gun. The difference between the thickness of the metal at the mouth and at the breech of a piece of ordnance.
     On account of the dispart, the line of aim or line of metal, which is in a plane passing through the axis of the gun, always makes a small angle with the axis.   --Eng. Cys.
  2. Gun. A piece of metal placed on the muzzle, or near the trunnions, on the top of a piece of ordnance, to make the line of sight parallel to the axis of the bore; -- called also dispart sight, and muzzle sight.