Malfeasance

The performance of an act which is contrary to official obligations.

Example: A Federal Communications Commission staff member accepts a bribe in exchange for expediting the processing of a license application for a TV station.

Malice

The desire to harm others, or to see others suffer.

Example: The same Federal Communications Commission staff member who accepted a bribe to expedite the processing of one application takes the three competing applications and runs them through the paper shredder. This particular act may also be one of malfeasance, but it's overwhelmingly malicious, as well, in that the applicants will be directly harmed by having their applications discounted.

Misfeasance

The improper or illegal performance of an otherwise lawful act, resulting in harm to someone.

Example: The same Federal Communications Commission staff member uses her inside knowledge of the applications already filed to tell her husband, head of a giant broadcast conglomerate, exactly how to word his application so that it will be considered "better" on merit than any others already submitted. The husband's application is ranked by the FCC as #1 on merits, while others are ranked lesser (harmed).

Negligence

The omission or neglect of any reasonable care, precaution or action, which may or may not result in harm to someone.

Example: The Federal Communications Commission staff member lets checks written to the FCC for license renewal fees pile up in a desk drawer without any accountability for when they were filed, or when they should be processed for deposit.

Nonfeasance

The failure to perform an act which is obligated or required, resulting in harm to someone.

Example: The same naughty, naughty Federal Communications Commission staff member fails to issue a written receipt to broadcasters for fees paid to the agency. Here again, this is probably negligent, as well, but it's primarily nonfeasance in that a task which is obligated for performance was not done.