Ok, I recommended many definitions for
deletion. It seems everybody has thier personal version of
mafia's history. I am
Sicilian and the study of the Mafias (we prefer plural vs one single mafia) is one of my interests, as a Sicilian and as a student. Also... I'm no member of any "family" you may think of.
The word itself has rather obscure origins, and its history and meaning is totally unrelated with modern concept of mafia.
Modern Mafias have so many different aspects I couldn't say if one is
wronger than others. Nowadays the term "Mafia" can be rightly (and sadly) related to almost every socio-political aspect of our lives. We could say the word itself has gained a more general and complex meaning since its migration from
Sicily to USA.
As regards the word itself: its origin can be traced back in the centuries. Sure it had something to do with the many invasions Sicily was exposed to. During the ages, Sicily has been invaded by pretty much ALL of the peoples in the Mediterranean Area: Greeks, Romans, Normands (~French), Arabs, Spanish, Italians nowadays. This gave
the island's culture an inmense richness, but as a side effect created among
Sicilians some sort of silent "brotherhood" against anyone coming from the outside world.
This "brotherhood", meaning protection of the masses from the invasors, lately degenerated into an oppression of the masses. The term mafia, originally indicating (not meaning) a group of people "respected" for being charismatic members of that brotherhood, slightly but inesorably turned into a synonym for
organized crime.
My personal idea is that the two different meanings still
coexist in Sicilian culture, often originating a confusig and ambiguous mix.
As regards the "international" meaning... well I guess everybody has a very distorted
prespective, maybe the best definition is "Those loud mouth Italian criminals talking with gestures like in the class A movie The Godfather"!