Definition of epistles:
(n) :
(Christianity) One of the books of the New Testament which was originally a letter issued by an apostle to an individual or a community.
(n) :
(chiefly literary or humorous) A letter, especially one which is formal or issued publicly.
(n) :
A literary composition in the form of a letter or series of letters, especially one in verse.
(v) :
(transitive) (chiefly literary or humorous) To write (something) in, or in the form of, a letter.
(v) :
To write a letter.
(v) :
To communicate with someone through a letter.