Land, say, redeveloped around river island (5)
I believe the answer is:
syria
'land' is the definition.
(Syria is an example)
'say redeveloped around river island' is the wordplay.
'redeveloped' is an anagram indicator.
'around' means one lot of letters goes inside another.
'river' becomes 'r' (abbreviation for river).
'island' becomes 'i' (geographical abbreviation).
'say' is an anagram of 'sya'.
'r'+'i'='ri'
'sya' enclosing 'ri' is 'SYRIA'.
(Other definitions for syria that I've seen before include "Middle Eastern country" , "In Mediterranean area" , "Middle-Eastern country" , "Asian country" , "Country E. of Lebanon" .)