Word Origin & History
peninsula of southern Greece, c.1490, from L., from Gk. Peloponnesos, second element apparently nesos "island," first element said to be named for Pelops, son of Tantalus, who killed him and served him to the gods as food (they later restored him to life). The proper name is probably from pellos "dark"
+ ops "face, eye." But the association with the peninsula name likely is folk etymology.