Definition of blackwashes:
(n) :
(slang, New Zealand) A whitewash victory for any New Zealand national sporting team.
(n) :
(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.
(n) :
(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.
(n) :
(chiefly politics) A villainization campaign.
(v) :
(transitive) To villainize, to present in a damaging light.
(v) :
(transitive) To cover with a black color.