villainous

A villainous person or act is very bad and often cruel.

When we call someone or something "villainous", it usually means they're doing evil things on purpose, like being mean to others for fun. It can also describe actions that cause harm, like hurting the environment. Sometimes people use this word to talk about movies, books, or games where the main character is a bad guy, like a villain in a story. In those cases, "villainous" just means their actions are wicked and evil.