offender UK /əˈfen.də(ɹ)/US /əˈfen.dɚ/ noun2 •One who gives or causes offense, or does something wrong.Almost all down trains are late, however; the empty wagon trains are probably the worst offenders and one or two hours' late running by them is not unusual. — 1961 •A person who commits an offense against the law, a lawbreaker. formsoffenders