Used by Sicilian gangs, it is now a separate branch of organized crime. It's meaning is literally, "This thing of ours". It goes back hundreds of years, when the Mafia was invented to protect Sicilian families from maurauding gangs and conquerers.
Lucy Luciano was known for bringing La Cosa Nostra to the United States.
by Lisa April 19, 2005
"Our Thing" or "This Thing Of Ours". The real name for the Mafia. Cosa Nostra is a crime sydicate that began in Sicily in the mid nineteenth century. A "Made Man" is a man that has become a member of Cosa Nostra. According to original Cosa Nostra rules, you had to be of Sicilian descent to be a member, you couldn't have a close relative that was a police officer, etc. Many political leaders have been murdered by Cosa Nostra.
Kiss the Don's ring or die. This is Cosa Nostra.
by Fear The Stiletto August 17, 2011