mal·fea·sance /ˌmal-'fēz-əns/ n [mal- bad + obsolete English feasance doing, execution, from Old French faisance, from fais-, stem of faire to make, do, from Latin facere]: the commission (as by a public official) of a wrongful or unlawful act involving or affecting the performance of one's duties compare misfeasance, nonfeasance
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.