In sport, a whitewash or sweep (N. America) is a series in which a person or team wins all games.
In Major League Baseball, teams typically play multiple games against each other. If one team wins all the games in that series, it's considered a 'series sweep', or, more commonly, simply a 'sweep'. In many cases, fans of the team in the favoured position, when all but one contest in the current series have been won, will bring brooms (either real brooms or large props for better visibility) to the ballpark with which to taunt the losing team.
On rare occasions, a season sweep can be accomplished, in which every contest between two teams is won by the same team. Intra-division season sweeps are relatively rare, since with the relatively large number of games against intra-division teams (19 per divisional matchup), the division rivals are more likely to find at least one lucky matchup. In cases where two teams only play each other once in the season, there is no distinction made between a series and season sweep.
In cricket, a whitewash is when a team wins all the matches played in a series of at least 3 matches.
The term whitewash is also used in rugby when one team loses every match in a particular series. The team that comes last in the Six Nations Championship has the ignominy of being awarded the wooden spoon, even if they have not suffered a complete whitewash.
In ATP and WTA tennis, the term whitewash is used when a player fails to win a game in a match (6-0, 6-0, 6-0; or 6-0, 6-0), also called a triple- or double-bagel respectively. Double bagels are more common.