depression associated with the reduction of daylight during the shorter days of late autumn and winter; abbr. SAD
seasonal affective disorder sea·son·al affective disorder (sē'zə-nəl)
n.
Abbr. SAD
A mild form of depression occurring at certain seasons of the year, especially depression that recurs in winter and that is characterized by loss of energy and sexual drive, restlessness, and often by a craving for carbohydrates.