Turning sea into land (7)
I believe the answer is:
estonia
'land' is the definition.
(Estonia is a country)
'turning sea into' is the wordplay.
'turning' indicates anagramming the letters.
'sea'+'into'='seainto'
'seainto' is an anagram of 'ESTONIA'.
(Other definitions for estonia that I've seen before include "European country, capital Tallinn" , "On a site (anag)" , "So eat in here in Eastern Europe" , "Baltic republic, capital Tallinn" , "Republic in the Baltic region, once part of USSR" .)