Greek resort island (5)
'greek resort island' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for corfu that I've seen before include "Largest Ionian Island" , "holiday venue!" , "Greek island, a British protectorate in C 19" , "Gk. island, opposite Albania" , "holiday destination?" .)
(Another definition for mykonos that I've seen is " holiday island".)