Yours, Etc.: Origins and Uses of 8 Sign-Offs
1890, from French fin de siècle "end of century," phrase used as an adjective. At the time it meant "modern;" now it means "from the 1890s." "App. first in title of a comedy, Paris fin de siècle, produced at the Gymnase, Feb. 1890" [Weekley]. French siècle "century, age" is from Latin saeculum (see secular).
The end of the nineteenth century; the phrase is French for “end of the century.” Fin de siècle is particularly used to describe the period's self-conscious artistic movements and a sophisticated despair that became popular at the time. Oscar Wilde is one of the best-known fin-de-siècle figures.