Isle of Napoleon's exile (4)
I believe the answer is:
elba
'isle of napoleon's exile' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elba that I've seen before include "Napoleon's exile isle" , "Napoleon's plaint: 'Able was I ere I saw . . . .'" , "Able was I ere I saw ... (palindrome)" , "Napoleonic island" , "Island of Napoleon's first exile" .)