In Lyon, sixteen diamonds confiscated (6)
I believe the answer is:
seized
'confiscated' is the definition.
('seize' can be a synonym of 'confiscate')
'in lyon sixteen diamonds' is the wordplay.
I cannot quite understand how this works, but
'diamonds' could be 'd' (abbreviation in bridge say) and 'd' is located in the answer.
The remaining letters 'seize' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for seized that I've seen before include "Took by force" , "Took hold of" , "Appropriated, contraband perhaps" , "Grabbed hold of" , "Caught" .)