Latin villa (country estate) gave villanus, the estate worker. Old French vilain carried lowborn, coarse; Middle English vileyn named the feudal serf class. The slide to criminal was complete by the 15th century: poverty filed as character flaw, in writing, by the literate class.
The pattern once seen: churl (from ceorl, freeman), boor (farmer), knave (boy, servant) all decayed into insults, while gentle, noble, and courteous (the words of the landed) became virtues. The vocabulary is the manor's own court record.
Villa's family: village, villein, and the French vilain still meaning nasty. Under PIE the estate word ties to weik- (settlement, clan), which also built vicinity and, by the Greek route, economy (household management). Every villain lives next door to your economics.
Who writes the dictionary, the villa or the field?