There's not much that's to his credit presumably (8)
I believe the answer is:
bankrupt
'there's not much that's to his credit presumably' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is the entire clue.
Can you help me to learn more?
(Other definitions for bankrupt that I've seen before include "Gone bust in business" , "Penniless" , "With no redeeming qualities" , "By no means" , "Person legally declared to be unable to pay debts" .)