Nonfeasance is a noun that refers to the failure to perform an act that is required by law. 

The Latin word facare (fah CAR ay) means to do. The addition of the prefix N-O-N –  meaning ‘no’ or ‘not’ –  means that our word of the day is a reference to not doing something, in this case something that is demanded by legal responsibility. Frequently used in law, nonfeasance has been with us since the early 17th century. Here’s an example:

The jury ruled that James was guilty of nonfeasance by not correcting the problem with the wiring. Essentially, they were saying that because he failed to repair the damaged wires, he was responsible for the ensuing fire that took place.