" The common Greek language as distinct from Classical Greek." The Septuagint and the Christian Scriptures (New Testament) were written in Koine Greek.
a common language used by speakers of different languages; "Koine is a dialect of ancient Greek that was the lingua franca of the empire of Alexander the Great and was widely spoken throughout the eastern Mediterranean area in Roman times"
(Gr., "shared or common"): the Greek of the Hellenistic World; it was the language of the cities founded by Alexander the Great and his successors. Koine was utilized for the translation of the Old Testament and New Testament.