Greek was a language that originated in Greece.
The Rosetta Stone was written in both Egyptian hieroglyphs and Greek. This allowed the Greek-speaking archaeologists to translate the hieroglyphic script, which they didn't know, into Greek. (PROSE: Love and War, AUDIO: Love and War)
In 64, the First Doctor witnessed the translation of the Gospel of Mark from Hebrew and Aramaic into Greek. (PROSE: Byzantium!)
In 950, the Necronomicon was translated from Arabic to Greek by Theodorus Philetus, but all such copies were burned in 1050. (PROSE: The Banquo Legacy)
Jo Grant's command of the Greek language was a bit faulty, as she accidentally asked for a kilo of peaches when she intended to ask for fruit juice. (PROSE: The Seismologist's Story)
In the 1970s, the Master, while posing as a Greek professor, used the alias Thascalos, which was Greek for Master. (TV: The Time Monster)