I assume coine is a typo for koine. It means 'common' in Greek and is used as the name of the Greek dialect (or amalgam of dialects) commonly spoken throughout the Eastern Mediterranean after the conquests of Alexander the Great (died 323 BC). Literary figures imitated the usage of the classical writers of the 5th and 4th centuries BC, but koine is what people actually spoke. It is the language the Septuagint (the Greek translation of the Old Testament) and the New Testament are written in.

Bingley