Other forms: whitewashes
A whitewash is an attempt to cover up wrongdoing. Dismiss it as a whitewash, a whitewash of an inquiry, whitewash the report.
The literal thing is cheap lime paint that hides what is underneath without repairing it, which is exactly the metaphor. In sport a whitewash is a series won without dropping a single match, and that sense has nothing to do with concealment.
1nounwhitewashAn attempt to cover up wrongdoing.
“Critics said the inquiry was a whitewash designed to protect senior officers.”
whitewash is a cover-up.
White plus wash, first the lime paint. The sense of concealment followed in the eighteenth century.
New Latin
lōtiō alba
English, today
whitewash
The is derived from white + wash. drug is a New Latin lōtiō alba literally “white wash”. The is derived partly from white + wash, and partly from the noun.
Etymology from Wiktionary, CC BY-SA