资料来源 : Webster's Revised Unabridged Dictionary (1913)

Reducing \Re*du"cing\ (r?*d?"s?ng),
   a & n. from {Reduce}.

   {Reducing furnace} (Metal.), a furnace for reducing ores.

   {Reducing pipe fitting}, a pipe fitting, as a coupling, an
      elbow, a tee, etc., for connecting a large pipe with a
      smaller one.

   {Reducing valve}, a device for automatically maintaining a
      diminished pressure of steam, air, gas, etc., in a pipe,
      or other receiver, which is fed from a boiler or pipe in
      which the pressure is higher than is desired in the
      receiver.