/ Dictionary / Index R reduction ratio: Meaning and Definition of Find definitions for: reduc'tion ra"tio Pronunciation: [key] an expression of the number of times by which an original document has been reduced in a microcopy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. reduction potential reductive Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language