Evidence of debts, earlier run up, without interest (9)
I believe the answer is:
incurious
'without interest' is the definition.
(I've seen this before)
'evidence of debts' is the wordplay.
'evidence of' becomes 'incur' (I can't explain this - if you can you should believe this answer much more).
'debts' becomes 'IOUs' (promises to pay debts).
'incur'+'ious'='INCURIOUS'
'earlier run up' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for incurious that I've seen before include "Lacking inquisitiveness" , "without interest" .)