fin de siècle

CIDE DICTIONARY

fin de siècle,  [F.].

 Lit., end of the century; -- mostly used adjectively in English to signify: belonging to, or characteristic of, the close of the 19th century. At that time the phrase was also intended to imply “modern” or “up-to-date;” as, fin-de-siècle ideas.
"As the twentieth century comes to a close, the meaning may change."  [Webster 1913 Suppl.]