Opposite of credit (5)
I believe the answer is:
debit
'opposite of credit' is the definition.
('debit' is the opposite to 'credit')
This is the entire clue.
(Other definitions for debit that I've seen before include "Payment made or owed" , "Take money away from" , "Enter in accounts as sum owed" , "entry on left" , "It's not to one's credit" .)