'unassuming' originates from the prefix 'un-' meaning 'not' and the word 'assuming' from Latin 'assumere', where 'ad-' meant 'to' and 'sumere' meant 'take'.

'assumere' transformed into the Old French word 'assumer', and eventually became the modern English word 'assume', with 'unassuming' forming as a negation.

Initially, 'assume' meant 'to take to oneself', but 'unassuming' evolved to mean 'not taking on airs or pretensions'.