Having a bad name, there must be no nonsense raised over debts (9)
I believe the answer is:
notorious
'having a bad name' is the definition.
(I've seen this before)
'no nonsense raised over debts' is the wordplay.
'nonsense' becomes 'rot' (rot can mean nonsense or rubbish).
'raised' says the letters should be written backwards (going up in a down clue).
'over' says to put letters next to each other.
'debts' becomes 'IOUs' (promises to pay debts).
'rot' back-to-front is 'tor'.
'no'+'tor'+'ious'='NOTORIOUS'
'there must be' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for notorious that I've seen before include "Famous for misdeeds" , "Infamous" , "Disgraceful" , "Hitchcock film" , "Having a bad name" .)