epistolary

Epistolary was formed from the noun epistle, which refers to a composition written in the form of a letter to a particular person or group. In its original sense, epistle refers to one of the 21 letters (such as those from the apostle Paul) found in the New Testament. Dating from the 13th century, epistle came to English via Anglo-French and Latin from the Greek noun epistolē, meaning "message" or "letter." Epistolē, in turn, came from the verb epistellein, meaning "to send" to or "to send from." Epistolary appeared in English four centuries after epistle and can be used to describe something related to or contained in a letter (as in "epistolary greetings") or composed of letters (as in "an epistolary novel").