Result of converting sea into land (7)

I believe the answer is:

estonia

I'm a little stuck... Click here to teach me more about this clue!

'land' is the definition.
(Estonia is a country)

'result of converting sea into' is the wordplay.
'sea into' anagrams to 'ESTONIA'.
However, I'm not clear how this is indicated.

Can you help me to learn more?

(Other definitions for estonia that I've seen before include "Country on the Baltic Sea" , "So eat in poorly on the Baltic Sea" , "East European country" , "Northern European country" , "So eat in here in Eastern Europe" .)

I've seen this clue in The Globe and Mail.

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