Mafiosi are defined by supplying protection, not by any particular profession

Evidence

In theory, the position of mafioso need not (and in practice does not) correspond to a particular profession. It does not matter whether the local mafioso is a cart driver, priest, doctor, lawyer, campiere, wheat dealer, or gabelloto, so long as he supplies protection. — Diego Gambetta, The Sicilian Mafia The Business of…, 210

Categorization

• DEFINE: Defines the mafioso by function (protection supplier) rather than by occupation, which is central to the book’s whole argument.