Definition of phlegmon in US English:

phlegmon

noun

Medicine
  • An inflammatory mass or localized area of inflammation; diffuse, spreading inflammation, often with suppuration, especially of soft tissue; cellulitis.

Origin

Late Middle English; earliest use found in John Trevisa (c1342–?1402), translator. From Anglo-Norman flegmon and Middle French fleugmon, flegmon, phlegmon and its etymon post-classical Latin phlegmon, phlegmone inflammation, inflamed tumour from ancient Greek ϕλεγμονή from ϕλέγειν to burn + -μονή, suffix forming nouns.