What does it mean to say that a person is a villain? What kind of person is a villain? What are the characteristics?

Strong but mediocre, jealous, schadenfreude, slander, no dignity, no principle, doing things by hook or by crook, honest and friendly in appearance, but in fact treacherous and smooth, secretive ... I need sympathy. Robbers who fight with naked fire and executioners who kill without blinking an eye are all villains, not villains. The villain has no courage, and the villain needs to hide. They have repeatedly explained to others that they are the most miserable people in the world, that they are weak, and that they cannot be weaker. It seems that life is meant to be bullied. When they try to devour other people's property rights, reputations and even their own lives, they even let their deep guttural voices, tearful eyes, trembling cheeks and the tone of wanting to say goodbye go into battle together. When the logic doesn't make sense, they choke and swallow it.