Book of EEC policy and translation (12)
I believe the answer is:
encyclopedia
'book' is the definition.
(encyclopedia is a kind of book)
'eec policy and translation' is the wordplay.
'translation' indicates anagramming the letters.
'eec'+'policy'+'and'='eecpolicyand'
'eecpolicyand' anagrammed gives 'ENCYCLOPEDIA'.
'of' is the link.
(Other definitions for encyclopedia that I've seen before include "Reference book" , "Book of knowledge" , "Reference work" .)