rainwash

From rain +‎ wash.

rainwash (countable and uncountable, plural rainwashes)

1. (geography) The washing action of rain, capable of erosion and transporting soil.
2. A deposit formed by rain.

rainwash (third-person singular simple present rainwashes, present participle rainwashing, simple past and past participle rainwashed)

1. To wash by the action of rain.