letters secretglossary / LETTERS SECRET letters secret. Hist. A governmental document that is issued to a private person, closed and sealed, and thus not made available for public inspection. — Also termed letters close. Cf. LETTERS PATENT(1). 词条贡献者 双语律师Virginia,国内知名法学院民商法专业,擅长翻译各类与公司与并购相关的法律文件。