[sun.set] n (14c) 1: the apparent descent of the sun below the horizon; also: the accompanying atmospheric effects
2: the time when the upper limb of the sun disappears below the horizon as a result of the diurnal rotation of the earth
3: a period of decline; esp: old age
[2]sunset adj (1976): stipulating the periodic review of government agencies and programs in order to continue their existence "~ law"