The Collaborative International Dictionary of English v.0.48:

Shunt \Shunt\, n. [Cf. D. schuinte slant, slope, declivity. See
   Shunt, v. t.]
   1. (Railroad) A turning off to a side or short track, that
      the principal track may be left free.
      [1913 Webster]

   2. (Elec.) A conducting circuit joining two points in a
      conductor, or the terminals of a galvanometer or dynamo,
      so as to form a parallel or derived circuit through which
      a portion of the current may pass, for the purpose of
      regulating the amount passing in the main circuit.
      [1913 Webster]

   3. (Gunnery) The shifting of the studs on a projectile from
      the deep to the shallow sides of the grooves in its
      discharge from a shunt gun.
      [1913 Webster]

   Shunt dynamo (Elec.), a dynamo in which the field circuit
      is connected with the main circuit so as to form a shunt
      to the letter, thus employing a portion of the current
      from the armature to maintain the field.

   Shunt gun, a firearm having shunt rifling. See under
      Rifling.
      [1913 Webster]