| backwash [`bak´wäsh] CHEMICAL ENGINEERING 1. In an ion-exchange resin system, an upward flow of water through a resin bed that cleans and reclassifies the resin particles after exhaustion. 2. See <<blowback>> OCEANOGRAPHY 1. Water or waves thrown back by an obstruction such as a ship or breakwater. 2. The seaward return of water after a rush of waves onto the beach foreshore. |