A villain (also known as, “baddie”, “bad guy”, “evil guy”, “heavy” or “black hat”) is an “evil” character in a story, whether a historical narrative or, especially, a work of fiction.
The villain usually is the antagonist (though can be the protagonist), the character who tends to have a negative effect on other characters. A female villain is occasionally called a villainess. Random House Unabridged Dictionary defines villain as “a cruelly malicious person who is involved in or devoted to wickedness or crime; scoundrel; or a character in a play, novel, or the like, who constitutes an important evil agency in the plot”.
Villains as a group.
“The local villainry were no doubt responsible.”
Evil or wicked character or behaviour.
A wicked or treacherous act.