/ Dictionary / Index R reductase test: Meaning and Definition of Find definitions for: reduc'tase test" Pronunciation: [key] a test for the bacterial content in milk to determine its fitness for drinking. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. reductase reductio ad absurdum Related Content Daily Word Quiz: nonchalant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language