The erosion of the bed of a stream by running water, principally by attrition of the detritus carried along by the stream, but also by the solvent action of the water
corrasion
الواصلة
cor·ra·sion
النطق
علم أصول الكلمات
() Ultimately from Latin corrasus, the past participle of corradere (“to scrape together”), itself from cor- (a form of con- 'together') + radere (“to scratch, scrape”).