NOUN (2)

1. a school of painters who used a technique of painting with tiny dots of pure colors that would blend in the viewer's eye; developed by Georges Seurat and his followers late in 19th century France;

2. a genre of painting characterized by the application of paint in dots and small strokes; developed by Georges Seurat and his followers in late 19th century France;

The Collaborative International Dictionary of English v.0.48:

Neoimpressionism \Ne`o*im*pres"sion*ism\
   (n[=e]`[-o]*[i^]m*pr[e^]sh"[u^]n*[i^]z'm), n. (Painting)
   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).
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

pointillism
    n 1: a school of painters who used a technique of painting with
         tiny dots of pure colors that would blend in the viewer's
         eye; developed by Georges Seurat and his followers late in
         19th century France
    2: a genre of painting characterized by the application of paint
       in dots and small strokes; developed by Georges Seurat and
       his followers in late 19th century France