/i pis"euhl/ , n.
1. a letter, esp. a formal or didactic one; written communication.
2. ( usually cap. ) one of the apostolic letters in the New Testament.
3. ( often cap. ) an extract, usually from one of the Epistles of the New Testament, forming part of the Eucharistic service in certain churches.
[ bef. 900; ME; OE epistol epistula, epistola epistolé message, letter, equiv. to epi- EPI- + stol- (var. s. of stéllein to send) + -e n. suffix ]