Buck that stops in London or Paris? (10)
I believe the answer is:
eurodollar
'buck that stops in london or paris?' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'buck' is the wordplay.
I cannot really understand how this works, but
'buck' could be 'dollar' (slang term for a dollar) and 'dollar' is found in the answer.
The remaining letters 'euro' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for eurodollar that I've seen is " International currency medium".)