Obscene overdraft piled on top of debts (6)
I believe the answer is:
odious
'obscene' is the definition.
(thesaurus)
'overdraft piled on top of debts' is the wordplay.
'overdraft' becomes 'od'.
'piled on' becomes 'i' (I can't justify this - if you can you should give a lot more credence to this answer).
'top of' means to remove the first letter (I've seen 'topped' mean this (to top something is to remove its top)).
'debts' becomes 'IOUs'.
'ious' with its first letter taken away is 'ous'.
'od'+'i'+'ous'='ODIOUS'
Can you help me to learn more?
(Other definitions for odious that I've seen before include "Really hateful, detestable" , "Hateful, really nasty" , "Unpleasant, repulsive" , "Vile" , "'Repugnant, foul (6)'" .)