'justly-executed' originates from the combination of 'justly' and 'executed'. 'Justly' comes from the Old French 'juste', meaning 'fair', and 'executed' from Latin 'executus', meaning 'carried out'.

'justly' evolved from the Old French 'juste', and 'executed' from the Latin 'executus', eventually forming the modern English term 'justly-executed'.

Initially, 'justly' meant 'fairly' and 'executed' meant 'carried out'. Together, they have maintained the meaning of 'performed in a fair manner'.