The Collaborative International Dictionary
Scumble \Scum"ble\, v. t. [imp. & p. p. Scumbled; p. pr. & vb. n. Scumbling.] [Freq. of scum. [root] 158.] (Fine Arts) To cover lighty, as a painting, or a drawing, with a thin wash of opaque color, or with color-crayon dust rubbed on with the stump, or to make any similar additions to the work, so as to produce a softened effect.
Wiktionary
vb. (en-past of: scumble)
Usage examples of "scumbled".
His face was pale and his chin scumbled with a half grown beard, but it was his features that lit first.
The man had fallen into the pile of armor, whose polished iron surfaces were now scumbled by damp leaves and streaks of grass and twigs and even feathers.
It was clearly unfinished, but the walls had been coloured in a deep terracotta, an Italian shade, and there was a scumbled gilt being applied around the window frames that set it off to perfection.
The flowerbeds, bordered with bricks buried diagonally, are pierced by dull red spikes that will be peonies, and the earth itself, scumbled, stone-flecked, horny, raggedly patched with damp and dry, looks like the oldest and smells like the newest thing under Heaven.
His neck and cheeks were scumbled with an impending beard, while his hair was matted into snarled ropes that writhed in a halo around his head.