[ri-doo-ser, -dyoo-]


a person or thing that reduces.
  1. an oxidizing solution for lessening the density of an exposed negative.
  2. a developing agent.
(in plumbing) a coupling decreasing in diameter at one end.Compare increaser(def 2).

Origin of reducer

First recorded in 1520–30; reduce + -er1
Related formsan·ti·re·duc·er, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for reducer

Historical Examples of reducer

  • Helen's next remark was in the natures of a reducer for the said expansion.

    The Portygee

    Joseph Crosby Lincoln

  • The alkali sets the reducer in action and is called the accelerator.

  • He is not to be dreaded by widows and orphans; he is a reducer of surplusage.

  • Or, is it king Nala the reducer of hostile towns that hath come here?

  • The destroyer of enemies,” “the reducer of the disobedient,” “the exterminator of rebels,” “he whose sword is good.


    John Francis Arundell

British Dictionary definitions for reducer



photog a chemical solution used to lessen the density of a negative or print by oxidizing some of the blackened silver to soluble silver compoundsCompare intensifier (def. 3)
a pipe fitting connecting two pipes of different diameters
a person or thing that reduces
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012