What does arrear mean?
An arrear is a sum of money that has fallen overdue — a payment that was due but has not been made. In modern English the word lives almost entirely in its plural form, "arrears," most often in the fixed phrase "in arrears," which describes someone who is behind on rent, mortgage installments, taxes, or other obligations. The term carries a formal, legal, and financial flavor: landlords, lenders, and courts speak of tenants falling into arrears or accounts remaining in arrears. Interestingly, not all uses imply wrongdoing — in accounting, being "paid in arrears" simply means compensation arrives at the end of a work period rather than in advance, a routine arrangement for many contractors and employees. Derived from Old French "arere," meaning "behind," the word literally captures the idea of lagging behind schedule. Its enduring usefulness lies precisely in that image: an arrear is a debt that has been left behind by time, waiting to be caught up.
nounAn amount of money that is owed and remains unpaid after it should have been paid; the word is now used almost exclusively in the plural form "arrears."
- Money that is overdue and unpaid — rent, taxes, mortgage installments, wages, or other payments that should already have been made (used almost exclusively in the plural, 'arrears').
- The state of being behind in fulfilling obligations, whether financial or otherwise (chiefly in the phrase 'in arrears').
"The tenant fell into arrears after missing two months of rent."
"After losing his job, he quickly fell into arrears on his mortgage."
"Freelancers on this contract are paid in arrears, at the end of each month."
The plural "arrears" is the overwhelmingly dominant form and is the usual way to express the concept; the singular "arrear" is rare and mostly confined to legal contexts.
"She was two months in arrears on her utility bills."
In British law, being 'in arrears' can cost you your home — this single little word sits behind thousands of evictions and repossessions every year.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of arrear
The word derives from the Anglo-Norman and Old French "arere" (modern French "arrière"), meaning "behind" or "in the back," which itself traces to Vulgar Latin *ad retro, from Latin "retro" ("backward"). It entered Middle English around the fourteenth century, initially in the general sense of being behind or in the rear, before narrowing to its financial sense of unpaid debts. It shares this backward-looking root with words such as "retrograde," "retard," and "rear" (as in rearguard).
Related word forms
How arrear is actually used
"Arrear" is a formal/legal register word that survives almost solely in the plural phrase "in arrears"; the bare singular is rare outside legal documents. In accounting, "paid in arrears" neutrally means payment occurs after the service period, not necessarily that anything is delinquent — a nuance worth noting since the phrase can describe normal billing practice.
Easily confused with arrear
Though they sound similar and share a final syllable, an error is a mistake, while an arrear is money overdue for payment.