Heel (professional wrestling)

In professional wrestling, a heel (also known as a rudo in Mexico) is a wrestler who portrays a villain, "bad guy", "baddie", "evil-doer", or "rulebreaker", and acts as an antagonist to the faces, who are the heroic protagonist or "good guy" characters. Not everything a heel wrestler does must be villainous: heels need only to be booed or jeered by the audience to be effective characters, although most truly successful heels embrace other aspects of their devious personalities, such as cheating to win or using foreign objects.

Source: Wikipedia — Heel (professional wrestling) (CC BY-SA 4.0)