Modern art is an umbrella term used to describe a range of artistic styles that emerged in the late 19th and early 20th centuries. It is characterized by a rejection of traditional forms and techniques, and instead focuses on experimentation and abstraction. The three letter answer for this crossword is 'ARE', which stands for the artistic movement of Abstract Expressionism. This movement was pioneered by American painters such as Jackson Pollock and Mark Rothko, and is considered to be one of the most influential art movements of the 20th century.