n :  a polymyxin produced by a bacterium of the genus Bacillus (B. polymyxa var. colistinus) and used against some gram-negative pathogens esp. of the genera Pseudomonas, Escherichia, Klebsiella, and Shigella .
 
   
 
Similar sounding terms:  gall·stone  gloss·odyn·ia 
 
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