Country's notes about island area (7)
I believe the answer is:
estonia
'country's' is the definition.
(I've seen this before)
'notes about island area' is the wordplay.
'about' indicates anagramming the letters.
'island' becomes 'i'.
'area' becomes 'a' (maths abbreviation).
'notes' anagrammed gives 'eston'.
'eston'+'i'+'a'='ESTONIA'
(Other definitions for estonia that I've seen before include "On a site (anag)" , "European country, capital Tallinn" , "Country due S. of Finland" , "One of the Baltic States" , "Republic in northeastern Europe" .)