Refers to an international style of art, literature, music, dance, and theater that flourished between 1905 and 1920, especially in Germany. The style is characterized by the abandonment of traditional standards of realism and proportion in favor of expressing the artist's emotions, resulting in distortions of line, color, and form.

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300021502