PENICILLIN

noun Etymology: New Latin Penicillium Date: 1929 any of several relatively nontoxic antibiotic acids of the general formula C 9 H 11 N 2 O 4 SR that are produced by molds (genus Penicillium and especially P. notatum or P. chrysogenum ) or synthetically and are used especially against gram-positive cocci, a salt or ester of a ~ or a mixture of such salts or esters