necrosisPronunciation: /nɛˈkrəʊsɪs/Definition of necrosis noun [mass 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: /-ˈkrɒtɪk/ adjective Origin: mid 17th century: modern Latin, from Greek nekrōsis (see necro-, -osis)necrosis in other Oxford dictionaries Definition of necrosis in the US English dictionary