Secret, private (12)

I believe the answer is:
confidential
This clue is a double definition.
'secret' is the first definition.
(synonyms)
'private' is the second definition.
(similar in meaning)
(Other definitions for confidential that I've seen before include "Inflicted on a (anag) - private" , "not expecting publication" , "Graham Greene's agent" , "Like T.S. Eliot's clerk" , "Classified" .)