Endorsed a couple of pages about Dover (8)
I believe the answer is:
approved
'endorsed' is the definition.
(thesaurus)
'a couple of pages about dover' is the wordplay.
'couple of' says to double the letters.
'pages' becomes 'p'.
'about' is an anagram indicator.
'p' doubled is 'pp'.
'dover' is an anagram of 'roved'.
'a'+'pp'+'roved'='APPROVED'
(Other definitions for approved that I've seen before include "Officially sanctioned" , "confirmed" , "Sanctioned, authorised" , "OK'd" , "Official" .)