'assumption' originates from Latin, specifically the word 'assumptio,' where 'ad-' meant 'to' and 'sumere' meant 'take.'

'assumptio' transformed into the Old French word 'assumpcion,' and eventually became the modern English word 'assumption' through Middle English.

Initially, it meant 'taking up or receiving,' but over time it evolved into its current meanings of 'belief without proof' and 'taking on responsibility.'