出处：按学科分类—语言、文字 中国对外翻译出版公司《汉英成语词典》第175页（198字）
形容行动极度秘密，无人察觉，例小偷在屋主度假期间，人不知，鬼不觉地搬空了整个房子。
While the occupants were away on holiday，the thieves，unnoticed by anyone，cleared their home of everything．