a secret association engaged in organized crime in the U.S., modeled after and affiliated with the Mafia.
Origin of Cosa Nostra
1960–65; < Italian: literally, our affair
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the branch of the Mafia that operates in the US
Word Origin for Cosa Nostra
Italian, literally: our thing
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
1963, "the Mafia in America," from Italian, literally "this thing of ours."
Online Etymology Dictionary, © 2010 Douglas Harper