1. the permanent cessation of physical and mental processes in an organism. In the United States in the early 1980s, the American Medical Association and the American Bar Association drafted and approved the Uniform Determination of Death Act, in which death is defined as either the irreversible cessation of core physiological functioning (i.e., spontaneous circulatory and respiratory functions) or the irreversible loss of cerebral functioning (i.e., brain death). Given the emergence of sophisticated technologies for cardiopulmonary support, brain death is more often considered the essential determining factor, particularly within the legal profession. See also assisted death; dying process; thanatology.

2. the degeneration or disintegration of a biological cell. See necrosis; neuronal cell death; programmed cell death.