'justly-acquired' originates from the combination of 'justly' and 'acquired'. 'Justly' comes from the Old French 'juste', meaning 'fair', and 'acquired' comes from the Latin 'acquirere', meaning 'to gain'.

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

Initially, 'justly' meant 'in a fair manner', and 'acquired' meant 'to gain'. Together, they have maintained the meaning of 'obtained in a fair manner'.