What does archipelago mean?
The definition of archipelago
Ar`chi*pel”a*go, n.; pl. -goes or -gos.
Etym: [It. arcipelago, properly, chief sea; Gr. pref Plague.]

1 The Grecian Archipelago, or Ægean Sea, separating Greece from Asia Minor. It is studded with a vast number of small islands.
2 Hence: Any sea or broad sheet of water interspersed with many islands or with a group of islands.