Extremely wicked, evil, or behaving like a villain in a story or movie.
From Old French 'vilein' meaning 'peasant or commoner', which carried negative associations. Over time, the word shifted to describe someone morally bad rather than of low social status.
It's wild that 'villainous' originally just meant 'peasant'—people were such snobs that they literally created evil connotations for common people, and those meanings stuck around for centuries!
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