misfeasance, malfeasance, or nonfeasance

Have heard malfeasance, but I haven't run across the other two before. So misfeasance is doing something wrong, but not necessarily illegal? And nonfeasance is failing to do something you're supposed to do?

I was hoping that nonfeasance was just a high-falutin' way of saying "Sittin' around not doing a thing," which would be a useful word ("I expect to be managing an unusually heavy load of nonfeasance and other related activities this weekend."), but it appears to be not so broadly applicable.