/ Dictionary / Index S streptothricin: Meaning and Definition of Find definitions for: strep•to•thri•cin Pronunciation: (strep"tu-thrī'sin), [key] — n. Pharm. an antibacterial substance produced by a soil fungus, Actinomyces lavendulae. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: streptothricin (Thesaurus) streptomycin Stresemann Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language