Synonyms for Gangrene (same or very similar meaning)
WordNet sense 1 (necrotic tissue; a mortified or gangrenous part or mass):
slough, sphacelus, sloughWordNet sense 2 (the localized death of living cells (as from infection or the interruption of blood supply)):
mortification, necrosisWordNet sense 3 (undergo necrosis):
mortify, necrose, sphacelateFrom the ODE community, based on WordNetadd/edit