See code is broken and Enigma's opening (7)
I believe the answer is:
diocese
'see' is the definition.
(thesaurus)
'code is broken and enigma's opening' is the wordplay.
'broken' is an anagram indicator.
'and' is a charade indicator (letters next to each other).
'opening' indicates taking the first letters.
The initial letter of 'enigmas' is 'e'.
'code'+'is'='codeis'
'codeis' anagrammed gives 'dioces'.
'dioces'+'e'='DIOCESE'
(Other definitions for diocese that I've seen before include "District under care of bishop" , "I see cod (anag)" , "Bishop's area" , "Jurisdiction of a bishop" , "Bishop's responsibility" .)