backwash(redirected from backwashes)
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1. a sucking movement of water, such as that of retreating waves
2. water washed backwards by the motion of oars or other propelling devices
3. the backward flow of air set up by an aircraft's engines
In an ion-exchange resin system, an upward flow of water through a resin bed that cleans and reclassifies the resin particles after exhaustion.
Water or waves thrown back by an obstruction such as a ship or breakwater.
The seaward return of water after a rush of waves onto the beach foreshore.