Hush hush reports etc, not opened, distributed (3,6)
I believe the answer is:
top secret
'hush hush' is the definition.
(thesaurus)
'reports etc not opened distributed' is the wordplay.
'not opened' means to remove the first letter.
'distributed' is an anagram indicator.
'reports'+'etc'='reportsetc'
'reportsetc' with its first letter removed is 'eportsetc'.
'eportsetc' with letters rearranged gives 'TOP-SECRET'.
(Other definitions for top secret that I've seen before include "Known to very few" , "As 007 mission" , "Very private" , "visible to hardly anyone?" , "As Bond mission" .)