omertà

PIE word *dʰéǵʰōm Unadapted borrowing from Italian omertà; further etymology uncertain—the following have been suggested: * from Spanish hombredad (“manliness”) (archaic), with the spelling aligned with Sicilian omu (“man”). Hombredad is derived from hombre (“man”) + -edad (variant of -dad (suffix forming nouns denoting a state of being)). However, the expected Sicilian output from a Spanish borrowing would have been *ummirità ~ *ummiritati. * from Sicilian umirtà (“humility”) (referring to the Mafia code’s requirement of obedience to the leader), from Latin humilitās (“obedience, submission”), from humilis (“humble; abject, submissive”) + -tās (suffix forming feminine abstract nouns denoting a state of being); with humilis from humus (“floor, ground; earth, soil”) + -ilis (suffix forming an adjective of relation). If so, the English word is a doublet of humility. However, the Oxford English Dictionary takes the view that this is “not well supported by the geographical distribution of the word”.

来源：wiktionary