Where does “郵便私書箱” come from?

郵便私書箱 (Japanese) comes from Japanese 私書箱, from Japanese 箱 — box.

郵便私書箱 (Japanese): a post office box

Definitions

  1. a post office box

Ancestry of “郵便私書箱”, step by step

郵便私書箱 traces back through two separate lines of ancestry.

via Japanese 私書箱

StepLanguageWordMeaning
1Japanese私書箱—
2Japanese箱box

via Japanese 郵便

StepLanguageWordMeaning
1Japanese郵便postal service; mail, postal matter
Every word from Japanese 箱 →Every word from Japanese 私書箱 →