[ ri-doo-ser, -dyoo- ]

  1. a person or thing that reduces.

  2. Photography.

    • an oxidizing solution for lessening the density of an exposed negative.

    • a developing agent.

  1. (in plumbing) a coupling decreasing in diameter at one end.: Compare increaser (def. 2).

Origin of reducer

First recorded in 1520–30; reduce + -er1

Other words from reducer

  • an·ti·re·duc·er, noun

Words Nearby reducer Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use reducer in a sentence

  • Very many, if not most, slides are all the better for just a touch of a "reducer" such as follows:—The ordinary "hypo."

  • To prepare this reducer, take one part varnish (the same varnish to be reduced), and two parts of turpentine.

British Dictionary definitions for reducer


/ (rɪˈdjuːsə) /

  1. photog a chemical solution used to lessen the density of a negative or print by oxidizing some of the blackened silver to soluble silver compounds: Compare intensifier (def. 3)

  2. a pipe fitting connecting two pipes of different diameters

  1. 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