Island in the Cyclades (3)
I believe the answer is:
ios
'island in the cyclades' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ios that I've seen before include "Apple's mobile system, in short" , "Greek island in the Cyclades" , "Greek island and mobile phone system" , "Greek isle" , "place?" .)