Cosa

Cosa is a term that can refer to several different subjects. It is the name of an ancient Roman town in southern Etruria, a common Italian word meaning "thing," and the basis of the well-known criminal organization Cosa Nostra, the Sicilian Mafia.

The ancient city of Cosa was a Roman colony established in the 3rd century BCE on the coast of Etruria, near the mouth of the Albegna River. It developed as a port and urban center with typical Roman public buildings. The site is now an archaeological park in Tuscany, preserving walls, a theater and other remains. Cosa declined and was largely abandoned in late antiquity as the harbor silted up and trade shifted elsewhere.

Cosa Nostra is the name used by the Sicilian Mafia to refer to its own organization, often translated as “our thing.” It emerged in Sicily and grew into a transregional criminal network with a formal code, families or cosche, and a governing commission. In the 20th century it became the subject of extensive law enforcement action, including large-scale trials and international investigations, and remains a focus of criminal justice efforts in Italy and abroad.

In Italian, cosa means “thing,” and the word appears in many idiomatic phrases.