misfeasance

The performance of an act which might lawfully be done, in an improper manner, by which another person receives an injury. It differs from malfeasance, or, nonfeasance.

It seems to be settled that there is a distinction between misfeasance and nonfeasance in the case of mandates. In cases of nonfeasance, the mandatary is not generally liable, because his undertaking being gratuitous, there is no consideration to support it; but in cases of misfeasance, the common law gives a remedy for the injury done, and to the extent of that injury.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.

Improperly doing something which a person has the legal right to do. Compare with malfeasance and nonfeasance. - (read more on Misfeasance)
  

The wrongful or injurious performance of an act that might havebeen lawfully done.