misfeasance

Misfeasance is a legal term for doing something lawful in an improper or careless way, especially when that poor performance causes harm. It sits between two related ideas: malfeasance (doing something inherently wrongful or illegal) and nonfeasance (failing to do something one has a duty to do).

Think of it as a spectrum of responsibility. Malfeasance is actively breaking the rules. Nonfeasance is failing to act when action is required. Misfeasance is taking action, but doing it so badly or carelessly that damage results. It usually does not focus on evil intent. Instead, it centers on failing to meet the expected standard of care while carrying out a duty.

The term often appears in discussions of public duty, official conduct, and negligence. For example, an official may have the authority to carry out a procedure, but if they do it carelessly and someone is harmed, that may be described as misfeasance. The key idea is that there was a duty to act properly, and the person fell short of the standard expected in that situation.

To prove misfeasance in a legal setting, it is usually necessary to show that the act was carried out improperly and that this failure caused real harm or loss. In that sense, the term reminds us that the way a duty is performed matters just as much as the duty itself: good intentions do not cancel out careless execution.