'arrearage' originates from Old French/Anglo-French, specifically the word 'arrere', where 'arrere' meant 'behind' (used with the noun-forming suffix '-age').

'arrearage' developed via Middle English from Anglo-French forms such as 'areerage' (based on 'arrere') and eventually became the modern English noun 'arrearage' (plural 'arrearages').

Initially it referred to 'the state of being behind' or 'behindness'; over time it came to refer particularly to 'sums of money that are behind or unpaid' (overdue payments).