Answer: hushhush

AnswerCrossword Clue
HUSHHUSHAdvice to Charlotte
HUSHHUSHStrictly confidential
HUSHHUSHTop secret
HUSHHUSHTop-secret
HUSHHUSHSecret
HUSHHUSHSupersecret.
HUSHHUSHCarried on with secrecy.
HUSHHUSHSecrecy: Colloq.
HUSHHUSHPolicy of concealment.
HUSHHUSHTop secret.
HUSHHUSHClassified
HUSHHUSHCovert
HUSHHUSHSuper-secret
HUSHHUSHAdvice to Sweet Charlotte