archipelago

n. group of small islands, chain of islands; body of water containing many islands

An archipelago is a chain or cluster of islands. The word archipelago literally means "chief sea", from Greek arkhon (arkhi-) ("leader") and pelagos ("sea"). In antiquity, the Archipelago (Greek: Αρхιπέλαγος) was the proper name for the Aegean Sea and, later, usage shifted to refer to the Aegean Islands (since the sea is remarkable for its large number of islands). It is now used to generally refer to any island group or, sometimes, to a sea containing a large number of scattered islands like the Aegea.
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(n.)
The Grecian Archipelago, or Aegean Sea, separating Greece from Asia Minor. It is studded with a vast number of small islands.
  

(n.)
Hence: Any sea or broad sheet of water interspersed with many islands or with a group of islands.
  

Noun
1. a group of many islands in a large body of water
(hypernym) land, dry land, earth, ground, solid ground, terra firma
(hyponym) Cape Verde Islands
(member-meronym) island