Definition Of backwash
clean (a filter) by reversing the flow of fluid through it.
The filters are backwashed every 24 hours to keep them clean.
the motion of receding waves.
This is succeeded by plane-bedded sands dipping gently seaward, which are produced by the swash and backwash of the waves on the beach face.
Example Of backwash
And I'd be surprised if some of the backwash of that hasn't carried into the international arena.
Apparently he was swept out to sea by a strong backwash .
As the rig barrelled by and the car shook, I heard the unmistakeable whine of air brakes mixing with backwash .
As the roiling backwash streamed past, it scoured around me, and when the froth cleared, there beneath my feet were multitudes of clams, all small and without hydroids.
At 15m a ledge with a boulder-strewn platform extended 30m to the foamy backwash near the cliffs.