The Collaborative International Dictionary of English v.0.48:

Whitewash \White"wash`\, v. t. [imp. & p. p. Whitewashed; p.
   pr. & vb. n. Whitewashing.]
   [1913 Webster]
   1. To apply a white liquid composition to; to whiten with
      whitewash.
      [1913 Webster]

   2. To make white; to give a fair external appearance to; to
      clear from imputations or disgrace; hence, to clear (a
      bankrupt) from obligation to pay debts.
      [1913 Webster]

   3. In various games, to defeat (an opponent) so that he fails
      to score, or to reach a certain point in the game; to
      skunk. [Colloq., U. S.]
      [Webster 1913 Suppl.]

   4. to gloss over or cover up (crimes or misfeasance).
      [PJC]

WordNet (r) 3.0 (2006):

whitewashed
    adj 1: coated with whitewash; "miles of whitewashed fences"