The word "unlawful" refers to something that is not allowed or prohibited by law. Some antonyms for "unlawful" could include permissible, lawful, legal, authorized, acceptable, valid, and legitimate. These words denote actions or behaviors that are allowed by law and do not violate any legal regulations. Therefore, if an action is lawful, it means that it is legal according to the established rules and regulations. For example, a lawful contract is one that meets all the legal requirements and is enforceable in court. Thus, antonyms for the word "unlawful" indicate the legality and compliance with the law.