Definition of arrear
1
: the state of being behind in the discharge of obligations
—usually used in plural
- They were in arrears with the rent. [=they had failed to pay the rent when it was due]
2 a
: an unfinished duty
—usually used in plural
- arrears of work that have piled up
b
: an unpaid and overdue debt
—usually used in plural
- paying off the arrears of the past several months
