rifampin
ri fam pin |riˈfampin rɪˈfæmpɪn |(also rifampicin |riˈfampəsin |) ▶noun Medicine a reddish-brown antibiotic used chiefly to treat tuberculosis and leprosy. [The antibiotic is obtained from the bacterium Nocardia mediterranei. ] ORIGIN 1960s: from rifam (yci )n (an antibiotic first isolated from the bacterium Streptomyces mediterranei ) + the insertion of pi- from piperazine .