scumble (sk
m
b
l)
verb:
1. To soften or blend (an outline or color) by covering with a thin coat of opaque or semiopaque color, or by rubbing.
2. To blur the outlines of (for example, to scumble the line between reality and fantasy).
noun:
1. Material used for scumbling, such as the opaque color that is applied.
2. The effect produced by scumbling.
Origin unclear, possibly derived from scum.