mis·con·duct • n. / misˈkänˌdəkt/ 1. unacceptable or improper behavior, esp. by an employee or professional person: she was found guilty of professional misconduct by a disciplinary tribunal. ∎ Ice Hockey a penalty assessed against a player for unsportsmanlike conduct.2. mismanagement, esp. culpable neglect of duties.• v. / ˌmiskənˈdəkt/ 1. (misconduct oneself) behave in an improper or unprofessional manner.2. [tr.] mismanage (duties or a project).