Payment made or owed (5)
I believe the answer is:
debit
'payment made or owed' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for debit that I've seen before include "It's not to one's credit" , "Payment made or owed" , "Charge" , "Accounting entry recording sums that are 5" , "left-side entry" .)