corrasion n 1: erosion by friction [syn: {abrasion}, {attrition}, {corrasion}, {detrition}]
Corrasion \Cor*ra"sion\ (k?r-r?"zh?n), n. [See {Corrade}.] (Geol.) 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. [1913 Webster]