necrosis Syllabification: (ne·cro·sis)Pronunciation: /neˈkrōsis/Definition of necrosis noun Medicine the death of most or all of the cells in an organ or tissue due to disease, injury, or failure of the blood supply. Derivatives necroticPronunciation: /-ˈkrätik/ adjective Origin: mid 17th century: modern Latin, from Greek nekrōsis (see necro-, -osis)necrosis in other Oxford dictionaries Definition of necrosis in the British & World English dictionary