'unjustly-performed' originates from the combination of 'unjustly' and 'performed', where 'unjustly' is derived from 'unjust', meaning 'not just or fair', and 'performed' from 'perform', meaning 'to carry out or execute'.

'unjustly' changed from the Old French word 'injuste' and eventually became the modern English word 'unjust'. 'Performed' comes from the Old French 'parfournir', meaning 'to accomplish'.

Initially, 'unjustly' meant 'not fair or equitable', and 'performed' meant 'carried out'. Together, they describe an action done in an unfair manner.