emphysematous phlegmon n : (pathology) a deadly form of gangrene usually caused by Clostridium bacteria that produce toxins that cause tissue death; can be used as a bioweapon [syn: {gas gangrene}, {clostridial myonecrosis}, {emphysematous gangrene}, {gangrenous emphysema}, {gas phlegmon}, {progressive emphysematous necrosis}]