Definition from Wiktionary, the free dictionary
backwash (plural backwashes)
- (nautical) The backward flow of water from oars or propeller or breaking waves.
- The similar flow of air from an aircraft engine.
- The result or consequence of an event; an aftermath.
- The saliva, spit or food particles that have flowed back into a drink after someone has drunk from it.
- To operate a water filter in the reverse direction in order to clean it.
backward flow of water from a propeller
similar flow of air from an aircraft engine