Areas surrounded by water (7)
I believe the answer is:
islands
'areas surrounded by water' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for islands that I've seen before include "Achill and Aran, say" , "Areas surrounded by water" , "Eg, Faroes" , "Ibiza, Corfu etc" , "Land masses with water on both sides" .)