sulphamethoxazole
noun(sul-fa-meth-ox-a-zole)
an antibacterial sulfonamide C10H11N3O3S used alone (as in the treatment of urinary tract infections or prophylaxis against meningococcal meningitis) or in combination with trimethoprim (as in the treatment of Pneumocystis carinii pneumonia, shigellosis, acute otitis media, or urinary tract infections)