A Chicago-based benevolent society for Sicilian immigrants, which developed into an Italian-American criminal organization similar to the Mafia.
The Unione Siciliana was renamed the Italo-American National Union in 1925.
Early 20th century; earliest use found in George M'Gowan (b. 1853). From Italian Unione Siciliana, lit. ‘Sicilian union’ from unione + Siciliana, feminine of Siciliano.