·add. ·noun A theory or practice which is a further development, on more rigorously scientific lines, of the theory and practice of Impressionism, originated by George Seurat (1859-91), and carried on by Paul Signac (1863- -) and others. Its method is marked by the laying of pure primary colors in minute dots upon a white ground, any given line being produced by a variation in the proportionate quantity of the primary colors employed. This method is also known as Pointillism (stippling).