PENICILLIN O(noun)Did you mean?Synonyms RhymesAlso try..penicillinpenicilliumpenicillinaseDefinitions There is 1 meaning of the phrase Penicillin O. Penicillin O - as a noun A penicillin that is similar in antibiotic action to penicillin g but is obtained differently Word Variations & RelationsAnagramsStarts PStarts PEStarts PENStarts PENIEnds OEnds NOEnds INOEnds LINOStarts P & ends OStarts PE & ends OStarts P & ends NOA-Z Proximitiespenicillation17penicillations18penicillia14penicilliform22penicillin14 Penicillin O penicillin-resistantpenicillinase17penicillinases18penicillins15penicillium17