art nouveau

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A style of decoration and architecture of the late 19th and early 20th centuries, characterized particularly by the depiction of leaves and flowers in flowing, sinuous lines.

Century Dictionary and Cyclopedia

1. A name given to a secession movement in art which had its origin in Paris at the close of the nineteenth century, and is still in process of development. It is concerned with architecture and the decorative arts chiefly. So far as the movement has any definite underlying principle, it is the negation of the conventional types which have attached themselves to art in the course of centuries and the realization of beauty by the proper management of necessary lines and values. In the hands of the practitioners, however, liberty has become libertinism, and results have been produced which have thrown discredit upon the movement.

Wiktionary

1. n. A decorative style of art and architecture that especially used the sinuous and flowing lines of plants.

WordNet 3.0

1. n. a French school of art and architecture popular in the 1890s; characterized by stylized natural forms and sinuous outlines of such objects as leaves and vines and flowers