What is the term for a villain or evil-doer?

The term "miscreant" refers specifically to a person who behaves badly or unlawfully, often associated with villainous or criminal behavior. This word captures the essence of someone who is involved in wrongdoing or malicious activities, making it an accurate descriptor of a villain or evil-doer.

The other terms do not convey the same meaning. "Malinger" refers to someone faking illness to avoid work or duty, which does not align with the notion of villainy. "Mitigate" means to make something less severe or serious, thus focusing on reducing harm rather than embodying harmful behavior itself. "Nadir" signifies the lowest point or a low state, typically in a non-moral context, and does not refer to a person or their actions. Therefore, "miscreant" is the most suitable term to define someone who embodies villainous traits or actions.