秘密
secret; covert; clandestine; confidential;private;januis clausis[拉](behind closed doors);in camera;in chamber;in private
~会议secret meeting; closed-door session;private session/~活动clandestine activities/~交易shady dealing/~警察secret police;secret policeman/~条约secret treaty/~投票secret ballot/~外交secret diplomacy/~文件secret papers;confidential document/~组织underground(or secret)organization