Epistle
EPIS'TLE, noun epis'l. [Latin epistola; Gr. to send to; to send.]
A writing, directed or sent, communicating intelligence to a distant person; a letter; a letter missive. It is rarely used in familiar conversation or writings, but chiefly in solemn or formal transactions. It is used particularly in speaking of the letters of the Apostles, as the epistles of Paul; and of other letters written by the ancients, as the epistles of Pliny or of Cicero.