Irreverent little demon collects debts (7)
I believe the answer is:
impious
'irreverent' is the definition.
(similar in meaning)
'little demon collects debts' is the wordplay.
I cannot quite understand how this works, but
'demon' could be 'imp' (I've seen this in other clues) and 'imp' is found in the answer.
'debts' could be 'ious' (promises to pay debts) and 'ious' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for impious that I've seen before include "9 [DEMON]" , "Lacking veneration or respect" , "Lacking reverence for God" , "Irreverent; wicked" , "Showing disrespect for a god" .)