'rightly-approved' originates from the combination of 'rightly,' meaning 'in a correct manner,' and 'approved,' meaning 'accepted as satisfactory.'

'Rightly' and 'approved' have been used in English since the Middle Ages, with 'rightly' deriving from Old English 'rihtlice' and 'approved' from Old French 'aprover.'

Initially, 'rightly' meant 'in accordance with justice,' and 'approved' meant 'to prove or demonstrate.' Over time, they combined to mean 'justifiably accepted.'