blackwash (plural blackwashes)
- (slang, New Zealand) a whitewash victory for any New Zealand national sporting team (also known as a blackout)
- (slang, cricket) a whitewash victory for the West Indies cricket team. Started in the 1984–86 "Blackwash" series of the West Indian cricket team in England in 1984.
- (medicine) A lotion made by mixing calomel and limewater.
- (slang, mining) public campaigns and advertising funded by the coal industry to draw attention away from environmentally unsustainable practices or to justify exclusion from carbon taxes.