The correct spelling of the word is "whitewashed" (/ˈwaɪtˌwɒʃt/), not "wast biased". The term refers to the act of covering up or glossing over flaws or mistakes, often in a dishonest or manipulative way. The word is derived from the practice of visually brightening up walls or fences with white paint or whitewash. The -ed suffix indicates that the action has already occurred, as in "whitewashed walls" or "whitewashed reputation".