a white, crystalline chelating drug, CHNOS, used to treat Wilson's disease, severe cases of rheumatoid arthritis, etc.
See penicillamine in American Heritage Dictionary 4
(pĕnˌĭ-sĭlˈə-mēnˌ)
noun
A degradation product of penicillin, C5H11NO2S, that is used as a chelating agent and in the treatment of rheumatoid arthritis, Wilson's disease, and lead poisoning.