Necrosis is a medical term used to describe the DEATH of cells or tissues in the body. It is often caused by injury or disease, and can be seen in conditions such as GANGRENE. The term necrosis is derived from the Greek word for 'DEATH, ' and is often used to describe the DEATH of cells or tissues due to injury or disease. GANGRENE is a type of necrosis that occurs when tissue dies due to lack of blood supply. It is characterized by discoloration and decay of the affected area.