whitewasher

noun

1. a mixture of lime, whiting, size, water, etc., for whitening walls, etc.
2. a cosmetic formerly used for making the skin fair
3. 1. a glossing over or concealing of faults or defects in an effort to exonerate or give the appearance of soundness
   2. something said or done for this purpose
4. ☆ Sports, Informal a defeat in which the loser scores no points

transitive verb

1. to cover with whitewash
2. to gloss over or conceal the faults or defects of; give a favorable interpretation of or a falsely virtuous appearance to
3. ☆ Sports, Informal to defeat (an opponent) soundly