- material eroded or swept away by rain.
Origin of rainwash
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for rainwash
It has been formed by rainwash from a hill of chalk, which must once have existed to the south.
Often much of the face of the cliff is covered with slip or rainwash, and overgrown with vegetation.
In winter the clays become semi-liquid, in summer the surface may be largely slip and rainwash, baked hard by the sun.