The term Greek or Grecian, refers to anything originating from the Earth nation of Greece or ancient Hellenic civilization, including the Greek people, language, and mythology.
Praxiteles was a master sculptor of ancient Greece whose pieces were considered priceless by the 20th century. (VOY: "The Killing Game")
In 2365, the hologram representing the noted comedian Ronald B. Moore mentioned a Greek person in one of his jokes. (TNG: "The Outrageous Okona")