Definition of "scumble"

scumble

/ˈskʌmbəl/

noun
countable and uncountable, plural scumbles
1. An opaque kind of glaze (layer of paint).
verb
third-person singular simple present scumbles, present participle scumbling, simple past and past participle scumbled
1. To apply an opaque glaze to an area of a painting to make it softer or duller.
  Quotations
  manure [...] dead leaves [...] and the odd unstomachable meal thrown or vomited there by this or that sensitive epicurean—all got scumbled together, eventually, by the knives of the seasons, to an impasto, feet thick, of unbelievable topsoil in which anything could grow
  1973, Thomas Pynchon, Gravity’s Rainbow
  "I want you to scumble the bottom third with sap green."
  1987, Bernard MacLaverty, short story. "The Drapery Man" (published in The Great Profumo and Other Stories, Jonathan Cape, 1987) - p.35
  The moon was brilliant, the path a track of scumbled footprints in the snow, the air cutting and cold.
  2000, Philip Pullman, The Amber Spyglass
  "Also —" indicating with the flat of his thumb the too-bright shine coming off the canvas: overly varnished."I agree. And here —" tracing midair the ugly arc where an over-eager cleaning had scrubbed the paint down to the scumbling.
  2013, Donna Tartt, The Goldfinch
2. To apply a painted pattern to the finish of a piece of furniture to simulate the woodgrain of another timber, as for example to give pine an appearance of oak.