| Noun | 1. | Peloponnesian Peninsula - the southern peninsula of Greece; dominated by Sparta until the 4th century BCEllas, Greece, Hellenic Republic - a republic in southeastern Europe on the southern part of the Balkan peninsula; known for grapes and olives and olive oil Sparta - an ancient Greek city famous for military prowess; the dominant city of the Peloponnesus prior to the 4th century BC Olympia - a plain in Greece in the northwestern Peloponnese; the chief sanctuary of Zeus and the site of the original Olympian Games |