What is the term for conducting a wrong or illegal act?

The term for conducting a wrong or illegal act is malfeasance. Malfeasance specifically refers to the performance of a wrongful or unlawful act, particularly by someone in a position of authority or responsibility. This term is often used in legal contexts to describe actions that are not only unethical but also violate the law, which differentiates it from other terms like misconduct, which might refer to improper behavior that doesn't necessarily break the law.

In contrast, misconduct encompasses a broader range of unethical behaviors, which may not always be illegal. Negligence involves a failure to act with the prudence that a reasonable person would exercise, leading to unintended harm or damage, but it does not inherently imply wrongdoing in the same way malfeasance does. Liability, on the other hand, relates to the legal responsibility for one's actions, rather than the actions themselves, and thus does not define a wrongful act. Therefore, malfeasance is the most accurate term in this context for describing an illegal or wrongful act.