Breadcrumb Home > Thesaurus > P Synonyms of penicillin Find synonyms for: Noun1. penicillin, antibiotic, antibiotic drugusage: any of various antibiotics obtained from Penicillium molds (or produced synthetically) and used in the treatment of various infections and diseasesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of penicillin (Dictionary) ✖ Related Content Daily Word Quiz: sepulture Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language