Pool the French bank's gold bullion? (6)
I believe the answer is:
lagoon
'pool' is the definition.
(I've seen this before)
'the french bank's gold bullion?' is the wordplay.
I cannot really understand how this works, but
'the french' could be 'la' ('the' in French) and 'la' is found within the answer.
The remaining letters 'goon' 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?
(Other definitions for lagoon that I've seen before include "Atoll's enclosed water" , "Shallow salt-water lake" , "Almost enclosed body of water" , "Inland sea" , "small lake" .)