epistolary
/ɪˈpɪstələrɪ/adjective
- relating to or denot-ing the writing of letters or literary works in the form of letters书信的; 书信体的：
an epistolary novel.
书信体小说。
词源
mid 17th cent.: from French épistolaire or Latin epistolaris, from epistola （see EPISTLE）.