ar·chi·pel·a·go (är'kə-pěl'ə-gō') n.
pl.ar·chi·pel·a·goes or ar·chi·pel·a·gos
A large group of islands: the Philippine archipelago.
A sea, such as the Aegean, containing a large number of scattered islands.
[Italian Arcipelago, the Aegean Sea, alteration (influenced by arci-, chief, archi-) of Medieval Latin Ēgēopelagus : Latin Aegaeus, Ēgēus, Aegean (from Greek Aigaios) + Latin pelagus, sea (from Greek pelagos; see plāk-1 in Indo-European roots).] ar'chi·pe·lag'ic (-pə-lāj'ĭk) adj.
1502, from It. arcipelago "the Aegean Sea" (13c.), from Gk. arkhipelagos, from arkhi- "chief" (see archon) + pelagos "sea." Aegean Sea being full of island chains, the meaning was extended in It. to "any sea studded with islands." Etymologists, noting the absence of arkhipelagos in ancient or Med.Gk. (the modern word in Gk. is borrowed from It.) believe it is an It. mistake for Aigaion pelagos "Aegean Sea" (M.L. Egeopelagus), or influenced by that name.
An electronic communications network formed in 1996 as one of the four original ECNs approved by the SEC. The network offers what is essentially a national and visible limit order book for stocks. In 2001 Archipelago received SEC approval to launch Archipelago Exchange (ArcaEx), an electronic stock market for New York Stock Exchange, American Stock Exchange, and Nasdaq securities. ArcaEx is operated as a regulated facility of the Pacific Exchange.