Refers generally to the style of painting, architecture, decorative arts, and applied arts that flourished in Europe and the United States from about 1890 to 1910. The style is characterized by an emphasis on fluid, undulating, or serpentine lines or contours based on organic forms and the use of modern materials such as iron and glass. The style developed as regional variations under various names.

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300021430