Actor Idris (4)
I believe the answer is:
elba
'actor idris' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elba that I've seen before include "''Able was I ere I saw . . . .'' (4)" , "place for Napoleon" , "Napoleon prison isle" , "Napoleon's Mediterranean exile island" , "Where emperor was confined" .)