[ bak-wosh, -wawsh ]
/ ˈbækˌwɒʃ, -ˌwɔʃ /


Nautical. water thrown backward by the motion of oars, propellers, paddle wheels, etc.
Aeronautics. the portion of the wash of an aircraft that flows to the rear, usually created by the power plant.Compare wash(def 31).
a condition, usually undesirable, that continues long after the event which caused it.

verb (used with object)

to affect, as by hitting, rocking, or splashing, with a backwash: a powerful cutter backwashing the skiers.
to clean out (a clogged filter) by reversing the flow of fluid: Backwash the swimming pool's filters regularly.


Origin of backwash

First recorded in 1765–75; back2 + wash

Related forms

back·wash·er, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for backwash

British Dictionary definitions for backwash


/ (ˈbækˌwɒʃ) /


a sucking movement of water, such as that of retreating wavesCompare swash (def. 4)
water washed backwards by the motion of oars or other propelling devices
the backward flow of air set up by an aircraft's engines
a condition resulting from a previous event; repercussion


(tr) to remove oil from (combed wool)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012