flatwash adjective 1noun 1verb 1forms 3 adjective1 •Pertaining to the methods or products of flatwash.Here he found a number of engravings some of which were enlivened with a certain amount of flatwash colour, mostly ochre. — 1949 noun1 •A style of painting in which shapes are completely filled with a solid color and have no outlines. verb1 •To paint in a uniform and unshaded color.The entrance to the block—a double door with frosted-glass panels—opened into a wide rectangular foyer flatwashed in cream. — 1957 formsflatwashed · flatwashing · flatwashes