An additional protective coating (as of paint or varnish)

Usage examples of overcoating.

There were no places to land, because now they were traversing the immense expanses of jungle where there were many small streams, but no rivers large enough to show through the overcoating of green growth.

His tone was the same one he had used on Dancer at the party Thursday night: quiet, even, but with an overcoating of venom.

The koyot's muzzle and the hair on his front legs were wet—or at least damp, with an overcoating of the sea-bottom sand plastered there by moisture.

Even all the land about us had taken a grim overcoating of gray which denied even the fresh green of the growth, all that I knew as life.