信しん書しょ

noun

letter; personal correspondence

Refers to written communication, often with a formal or official nuance. Commonly used in legal or business contexts.

• 信しん書しょの秘ひ密みつは法ほう律りつで守まもられている。

  The confidentiality of correspondence is protected by law.

• 会かい社しゃから重じゅう要ような信しん書しょが届とどいた。

  An important letter arrived from the company.