Source : Webster's Revised Unabridged Dictionary (1913)

Backwash \Back"wash`\, v. i.
   To clean the oil from (wood) after combing.

Source : WordNet®

backwash
     n 1: the flow of air that is driven backwards by an aircraft
          propeller [syn: {slipstream}, {airstream}, {race}, {wash}]
     2: the consequences of an event (especially a catastrophic
        event); "the aftermath of war"; "in the wake of the
        accident no one knew how many had been injured" [syn: {aftermath},
         {wake}]
     3: the wave that spreads behind a boat as it moves forward;
        "the motorboat's wake capsized the canoe" [syn: {wake}]