(Noun)
The official name given to the so-called "Elgin marbles" by the British Museum, and comprising the pictorial reliefs in stone taken by Lord Elgin from the Parthenon, Anthens, Greece, circa 1811. It could refer to any of those artifacts held elsewhere including Greece, but in practice this is the referent. This museum holding is controversial, and Greece often requests/demands their return.
Usage: Greece has once again demanded that the Parthenon marbles, currently held by the British Museum in London, be returned to Athens where there is a new museum dedicated to displaying them in the original context.