Definition of: Koine

(koi·nā′) noun
1. The common form of Greek, an outgrowth of the Attic dialect with many Ionic elements, used throughout the Greek world from the time of the conquests of Alexander to the sixth century A.D. Koine was the literary language of Aristotle and Plutarch, and was used in the Septuagint and the New Testament; in its spoken form it became the basis of virtually all modern Greek dialects.
2. Any mixed language that becomes the lingua franca of a region: also koine. [<Gk. koinē (dialektos) common (language)]