Confused smuggler carrying diamonds deserted at end of road (7)
I believe the answer is:
muddled
'confused' is the definition.
(muddling is a kind of confusing)
'smuggler carrying diamonds deserted at end of road' is the wordplay.
'smuggler' becomes 'mule'.
'carrying' means one lot of letters goes inside another.
'diamonds' becomes 'd' (abbreviation in bridge say).
'deserted' becomes 'd'.
'at end of' indicates one should take the final letters.
The last letter of 'road' is 'd'.
'd'+'d'='dd'
'mule' enclosing 'dd' is 'muddle'.
'muddle'+'d'='MUDDLED'
(Other definitions for muddled that I've seen before include "Disordered, confused" , "Confused, all mixed up" .)