'wrongfully-kept' originates from the combination of 'wrongfully' and 'kept', where 'wrongfully' is derived from 'wrong' meaning 'incorrect or unjust' and 'kept' is the past participle of 'keep', meaning 'to hold or retain'.

'wrongfully' evolved from Old English 'wrang' meaning 'injustice' and 'fully' from 'full', combined with 'kept', the past participle of 'keep', from Old English 'cepan'.

Initially, 'wrongfully' meant 'in a wrong manner', and 'kept' meant 'held or retained'. Together, they evolved to mean 'held in an unjust manner'.