'conclusively' originates from Latin, specifically the word 'conclusivus,' where 'con-' meant 'together' and 'claudere' meant 'to close.' 'Collected' comes from Latin 'collectus,' the past participle of 'colligere,' where 'com-' meant 'together' and 'legere' meant 'to gather.'

'Conclusively' changed from the Latin word 'conclusivus' and eventually became the modern English word 'conclusive.' 'Collected' transformed from the Latin 'collectus' through Old French 'collecter' and eventually became the modern English word 'collect.'

Initially, 'conclusively' meant 'to close together,' but over time it evolved into its current meaning of 'leaving no doubt.' 'Collected' initially meant 'gathered together,' which remains largely unchanged.