/ Dictionary / Index S subtilisin: Meaning and Definition of Find definitions for: sub•til•i•sin Pronunciation: (sub-til'u-sin), [key] — n. Biochem. a proteolytic enzyme produced by the bacterium Bacillus subtilis, used as an active ingredient in detergents and also in research to help reveal protein structure. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. subtile subtilize Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language