gouache

from WordNet (r) 3.0 (2006)

gouache
    n 1: an opaque watercolor prepared with gum
    2: a watercolor executed with opaque watercolors mixed with gum

from The Collaborative International Dictionary of English v.0.48

Gouache \Gouache\ (gw[.a]sh), n. [F., It. guazzo.]
   A method of painting with opaque colors, which have been
   ground in water and mingled with a preparation of gum; also,
   a picture thus painted.
   [1913 Webster]