archipelago

[William Hupy]

This is from Greek, meaning chief sea and initially referred only to the Aegean Sea as it is chiefly sea with a few scattered islands.

[Perry Lassiter]

No chance archa- could ever have referred to a chain or something similar? The object in question is not, in fact, a chief or even a minor sea, but islands.

[William Hupy]

I'm thinking it means chiefly sea. Think of Michael the ARCH angel, Michael the chief angel, or an ARCHbishop.

[Slava]

Courtesy of Etymonline

c.1500, from Italian arcipelago "the Aegean Sea" (13c.), from Greek arkhipelagos, from arkhi- "chief" (see archon ) + pelagos "sea" (see pelagic ). The Aegean Sea being full of island chains, the meaning was extended in Italian to "any sea studded with islands." Klein, noting the absence of arkhipelagos in ancient or Medieval Greek (the modern word in Greek is borrowed from Italian) believe it is an Italian mistake for Aigaion pelagos "Aegean Sea" (Medieval Latin Egeopelagus), or influenced by that name.