'undisputedly' originates from the prefix 'un-' meaning 'not' and the word 'disputed', which comes from Latin 'disputare', meaning 'to discuss or argue'.

'disputare' transformed into the Old French word 'disputer', and eventually became the modern English word 'dispute', leading to 'undisputedly'.

Initially, it meant 'not argued or challenged', and this meaning has largely remained the same in modern usage.