fin de siècle /ˌfæn də siˈɛklə/adjective 2noun 1forms 1 adjective2 •Pertaining to the close of the 19th century, usually suggesting a literary and artistic climate of modernism, world-weariness, and self-indulgence. •Pertaining to the close of the 20th (or any other) century.And, Dag, have you ever noticed that your bungalow looks more like it belongs to a pair of Eisenhower era Allentown, Pennsylvania newlyweds than it does to a fin de siècle existentialist poseur? — 1991 noun1 •The closing era of any century; (loosely) the end of any era. formsfins de siècle