backwash

From back +‎ wash.

• (UK) IPA^(key): /ˈbæk.wɒʃ/
• (US) IPA^(key): /ˈbæk.wɑʃ/

• Audio (Southern England):

  (file)

• Rhymes: -ækwɒʃ

backwash (countable and uncountable, plural backwashes)

1. (nautical) A backward flow of water, as from oars, a propeller, breaking waves, etc.
   • 1952, Ralph Ellison, Invisible Man, Penguin Books (2014), page 166:

     I looked back to a ferry passing the Statue of Liberty now, its backwash a curving line upon the bay.

   • 1999, Seamus Heaney, Beowulf, London: Faber and Faber, page 98:

     They pitched the dragon
     over the cliff-top, let tide's flow
     and backwash take the treasure-minder.

2. The similar flow of air from an aircraft engine.
3. The result or consequence of an event; an aftermath.
4. The saliva, spit or food particles that have flowed back into a drink after someone has drunk from it.
5. (economics) The situation where economic growth in one area harms other areas by attracting people and business away from those areas.
6. (education) washback

backwash (third-person singular simple present backwashes, present participle backwashing, simple past and past participle backwashed)

1. To operate a water filter in the reverse direction in order to clean it.
2. (transitive) To affect with backwash.
3. To clean the oil from wool after combing.

• backwash ileitis

• washback