A cut bank is the outside bank of a meander in a river, where erosion is actively occurring due to the higher velocity of water flow. Cut banks are important features in the study of fluvial geomorphology and river dynamics, as they contribute to the lateral migration of rivers and the formation of meandering channels.
Reference: Leopold, L. B., Wolman, M. G., & Miller, J. P. (1964). Fluvial Processes in Geomorphology. Dover Publications.