apoptosis
noun(ap-o-pto-sis)
a genetically directed process of cell self-destruction that is marked by the fragmentation of nuclear DNA, is activated either by the presence of a stimulus or removal of a suppressing agent or stimulus, is a normal physiological process eliminating DNA-damaged, superfluous, or unwanted cells, and when halted (as by gene mutation) may result in uncontrolled cell growth and tumor formation —called also cell suicide, programmed cell death