Ἔκδεια

[Meaning] the residue of what has been indebted. For 'arrears' is the part to pay, of what someone owes, even if not all of it; but 'deficit' [is] not paying it at all. Or 'arrears' is having something but not paying it, 'deficit' not having it at all -- such that the former is voluntary, the latter involuntary.¹
'Arrears' is a voluntary deprivation of money, 'deficit' an involuntary one.²