Other Irish/Irish Mob movies or tv shows?

And thats what we call a backronym folks.

From http://en.wikipedia.org/wiki/Mafia#Etymology

There are several theories about the origin of the term. The Sicilian adjective mafiusu may derive from the slang Arabic مهياص mahyas, meaning "aggressive boasting, bragging", or marfud meaning "rejected". Roughly translated, it means "swagger", but can also be translated as "boldness, bravado". In reference to a man, mafiusu in 19th century Sicily was ambiguous, signifying a bully, arrogant but also fearless, enterprising, and proud, according to scholar Diego Gambetta.[7]

According to the Sicilian ethnographer Giuseppe Pitrè, the association of the word with the criminal secret society was made by the 1863 play I mafiusi di la Vicaria (The Beautiful (people) of Vicaria) by Giuseppe Rizzotto and Gaetano Mosca, which is about criminal gangs in the Palermo prison.[8] The words Mafia and mafiusi (plural of mafiusu) are never mentioned in the play, and were probably put in the title because it would add local flair.

The association between mafiusi and criminal gangs was made by the association the play's title made with the criminal gangs that were new to Sicilian and Italian society at the time. Consequently, the word "mafia" was generated from a fictional source loosely inspired by the real thing and was used by outsiders to describe it. The use of the term "mafia" was subsequently taken over in the Italian state's early reports on the phenomenon. The word "mafia" made its first official appearance in 1865 in a report by the prefect of Palermo, Filippo Antonio Gualterio.

Leopoldo Franchetti, an Italian deputy who travelled to Sicily and who wrote one of the first authoritative reports on the mafia in 1876, saw the Mafia as an "industry of violence" and described the designation of the term "mafia": "the term mafia found a class of violent criminals ready and waiting for a name to define them, and, given their special character and importance in Sicilian society, they had the right to a different name from that defining vulgar criminals in other countries."[9] He saw the Mafia as deeply rooted in Sicilian society and impossible to quench unless the very structure of the island's social institutions were to undergo a fundamental change.[10]

According to popular myth, the word Mafia was first used in the Sicilian rebellion - the Sicilian Vespers - against the oppressive Anjou rule on 30 March 1282. Mafia is the acronym for "Morta Alla Francia, Italia Anela" (Italian for "Death to France. This is Italy's cry"). However, this version is discarded by most serious historians nowadays.

Try reading. Its helpful in not making you look ignorant.