Corrasion
Pronunciation : Cor*ra"sion (kr-r"zhn)
Part of Speech : n.
Etymology : [See Corrade.] (Geol.)
Definition : Defn: 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.
Source : Webster's Unabridged Dictionary, 1913