Answer:

topsecret

AnswerCrossword Clue
TOPSECRETClearance level
TOPSECRETHighest level of classified information
TOPSECRETClandestine
TOPSECRETLike an eyes-only document, say
TOPSECRETLike many briefings Obama is privy to
TOPSECRETHighly classified
TOPSECRETHush-hush
TOPSECRETFor certain eyes only
TOPSECRETVery hush-hush
TOPSECRETStrictly hush-hush.
TOPSECRETHush-hush.
TOPSECRETNot to be disclosed.
TOPSECRETVery hush-hush.
TOPSECRETClassified.
TOPSECRETPopular official stamp
TOPSECRETLike the Manhattan Project
TOPSECRETKnown to next to none
TOPSECRETTrained street cop to be covert (3-6)
TOPSECRETClassified
TOPSECRETPhrase often stamped in red
TOPSECRETOn a need-to-know basis
TOPSECRETUpper-level security clearance status