/ Thesaurus / C Synonyms of cosa nostra Find synonyms for: Noun1. Mafia, Maffia, Cosa Nostra, syndicate, crime syndicate, mob, familyusage: a crime syndicate in the United States; organized in families; believed to have important relations to the Sicilian MafiaWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language