Stop loan, wasting pound (3)
I believe the answer is:
end
'stop' is the definition.
(synonyms)
'loan wasting pound' is the wordplay.
'loan' becomes 'lend' (synonyms).
'wasting' suggests deleting specific letters.
'pound' becomes 'L' (abbreviation e.g. Lsd - pounds, shillings, pence).
'lend' with 'l' taken out is 'END'.
(Other definitions for end that I've seen before include "'Conclusion, finale (3)'" , "For Chelsea or Villa, it's a" , "Exterminate - object" , "Unyielding" , "Completion" .)