Black wash \Black" wash`\or Blackwash \Black"wash\, n.
1. (Med.) A lotion made by mixing calomel and lime water.
2. A wash that blackens, as opposed to {whitewash}; hence,
figuratively, calumny.
To remove as far as he can the modern layers of
black wash, and let the man himself, fair or foul,
be seen. --C. Kingsley.