/ Dictionary / Index R reducer: Meaning and Definition of Find definitions for: re•duc•er Pronunciation: (ri-d'sur, -dy'-), [key] — n. a person or thing that reduces. an oxidizing solution for lessening the density of an exposed negative. a developing agent. (in plumbing) a coupling decreasing in diameter at one end. Cf.(def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: reducer (Thesaurus) reduced paid-up insurance reducible Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language