e·pis·tle / iˈpisəl/ • n. formal a letter. ∎ a poem or other literary work in the form of a letter or series of letters. ∎ (also Epistle) a book of the New Testament in the form of a letter from an Apostle: St. Paul's epistle to the Romans. ∎ an extract from an Epistle (or another New Testament book not a Gospel) that is read in a church service.ORIGIN: Old English, via Latin from Greek epistolē, from epistellein ‘send news,’ from epi ‘upon, in addition’ + stellein ‘send.’ The word was reintroduced in Middle English from Old French.
Epistle also denotes an extract from an Epistle (or another New Testament book not a Gospel) that is read in a church service.
Epistle side in a church, the south end of an altar, from which the Epistle is traditionally read (opposite to the north or Gospel side).
So epistolary XV. f. F. épistolaire or L. epistolāris.