mis·fea·sance 
(mĭs-fēzəns)
(mĭs-fēzəns)n.
Improper and unlawful execution of an act that in itself is lawful and proper.
[Anglo-Norman mesfesaunce, from mesfere, to do wrong : mes-, wrongly (from Old French; see MIS-1) + fere, to do (from Latin facere; see dhē- in the Appendix of Indo-European roots).]