Definitions for "Atoll"
Keywords:  lagoon, reef, coral, island, submerged
A coral island or islands, consisting of a belt of coral reef, partly submerged, surrounding a central lagoon or depression; a lagoon island.
A circular reef that encloses a relatively shallow lagoon and extends from a very great depth to the sea surface. An atoll forms when an oceanic island ringed by a barrier reef sinks below sea level.
A ring of low coral islands surrounding a lagoon.
Keywords:  ussr, cis, missile, former, air
AA-2-2 air-to-air missile, CIS (former USSR)