noun
[ U ] ( abbr. SAD ) a medical condition in which a person feels sad and tired during late autumn / fall and winter when there is not much light from the sun
noun
[ U ] ( abbr. SAD ) a medical condition in which a person feels sad and tired during late autumn / fall and winter when there is not much light from the sun
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005