reversing engine

from The Collaborative International Dictionary of English v.0.48

Reversing \Re*vers"ing\, a.
   Serving to effect reversal, as of motion; capable of being
   reversed.
   [1913 Webster]

   {Reversing engine}, a steam engine having a reversing gear by
      means of which it can be made to run in either direction
      at will.

   {Reversing gear} (Mach.), gear for reversing the direction of
      rotation at will.
      [1913 Webster]