gouache 
(gwäsh, g
-äsh
)
n.1. a. A method of painting with opaque watercolors mixed with a preparation of gum.
b. An opaque pigment used when painting in this way.
2. A painting executed in this manner.
[French, from Italian guazzo, from Latin aquātiō, watering, from aquātus, past participle of aquārī, to fetch water, from aqua, water; see akw-ā- in the Appendix of Indo-European roots.]