The Collaborative International Dictionary of English v.0.48:

Locomotive \Lo"co*mo`tive\, n.
   A locomotive engine; a self-propelling wheel carriage,
   especially one which bears a steam boiler and one or more
   steam engines which communicate motion to the wheels and thus
   propel the carriage, -- used to convey goods or passengers,
   or to draw wagons, railroad cars, etc. See Illustration in
   Appendix.
   [1913 Webster]

   Consolidation locomotive, a locomotive having four pairs of
      connected drivers.

   Locomotive car, a locomotive and a car combined in one
      vehicle; a dummy engine. [U.S.]

   Locomotive engine. Same as Locomotive, above.

   Mogul locomotive. See Mogul.
      [1913 Webster] Locomotiveness

WordNet (r) 3.0 (2006):

locomotive engine
    n 1: a wheeled vehicle consisting of a self-propelled engine
         that is used to draw trains along railway tracks [syn:
         locomotive, engine, locomotive engine, railway
         locomotive]