|penəsə|lōik- noun
Etymology: penicill in + -oic
: an amido dicarboxylic acid that has the general formula RCONH(C 6 H 10 NS)(COOH) 2 and is obtained from a penicillin by hydrolytic opening of the lactam ring (as by mild treatment with alkali or by the action of a penicillinase)