Search Result for "penicillin o":
Wordnet 3.0

NOUN (1)

1. a penicillin that is similar in antibiotic action to penicillin G but is obtained differently; 



WordNet (r) 3.0 (2006):

penicillin O
    n 1: a penicillin that is similar in antibiotic action to
         penicillin G but is obtained differently