'bankroll' originates from English, specifically combining the words 'bank' and 'roll', where 'bank' referred to a financial institution and 'roll' referred to a roll or list (originally a roll of banknotes or capital).

'bankroll' first appeared as a noun in the mid 19th century meaning 'a roll of banknotes or capital for financing'. The verb sense 'to supply with funds' developed later from the noun and gave rise to forms such as 'bankrolled'.

Initially, it meant 'a roll of banknotes or capital', but over time it evolved into the verb meaning 'to provide financial support' and the participial/adjectival senses meaning 'having been funded'.