Permission given to break silence (7)
I believe the answer is:
license
'permission' is the definition.
(synonyms)
'to break silence' is the wordplay.
'to break' indicates an anagram (letters broken up and rearranged).
'silence' is an anagram of 'LICENSE'.
'given' is the link.
(Other definitions for license that I've seen before include "Silence (anag.)" , "Entitle" , "Authorise (something)" , "Silence about permission to sell" , "Authorise officially" .)