Cosa Nostra is the traditional name used by the Mafia to refer to their organization, which is Italian for "Our Thing". The term was adopted by the Italian press, as they needed a name to separate the Mafia from other organized crime organizations in Italy. It is widely used in the United States as a formal term for the Mafia.
The Sicilian Mafia has also used other names to describe itself throughout its history, such as "The Honoured Society". Mafiosi are known among themselves as "men of honour" or "men of respect".
In an effort to make Cosa Nostra sound more like a proper name, and to distinguish the American Mafia from their Sicilian counterparts, federal agents were responsible for the addition of the "La". The phrase, literally translated "the our thing", has been interpreted as "this thing of ours".