/ Dictionary / Index P peptone: Meaning and Definition of Find definitions for: pep•tone Pronunciation: (pep'tōn), [key] — n. Biochem. any of a class of diffusible, soluble substances into which proteins are converted by partial hydrolysis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: peptone (Thesaurus) peptolytic peptonize Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language