| atoll | One of three geomorphologically distinct types of coral reefs, the other two being fringing reefs and barrier reefs An atoll is an annular reef formed around a subsiding volcanic island See Barnes and Hughes (1988) | en |
| atoll | AA-2-2 air-to-air missile, CIS (former USSR) | en |
| atoll | a circular coral reef that encloses a shallow lagoon | en |
| atoll | A coral reef appearing in plan view as roughly circular, and surmounted by a chain of closely spaced, low coral islets that encircle or nearly encircle a shallow lagoon in which there is no land or islands of non-coral origin; the reef is surrounded by open sea GG | en |
| atoll | <))) | en |
| atoll | A circular reef surrounding a deeper lagoon (See page(s) 454) | en |
| atoll | A type of island consisting of a ribbon reef that nearly or entirely surrounds a lagoon and supports, in most cases, one to many islets on the reef platform. Atolls have a unique geology, so not all islands with a reef and a lagoon are atolls | en |
| atoll | A coral island or islands, consisting of a belt of coral reef, partly submerged, surrounding a central lagoon or depression; a lagoon island | en |
| atoll | an island consisting of a circular coral reef surrounding a lagoon | en |
| atoll | (Ah-tole) n a ring-like coral reef that nearly or entirely encloses a lagoon | en |
| atoll | Annular coral reef enclosing a lagoon which communicates or not with the open sea by one or more passes | en |
| atoll | 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 | en |
| atoll | circular, or near circular coral reef appearing as a low coral island or a ring of closely spaced coral islets encircling a shallow lagoon in which there is no pre-existing land, and surrounded by deep water of the open sea, formed above an underwater volcano | en |
| atoll | a ring-shaped coral reef or string of coral islands, usually enclosing a shallow lagoon | en |
| atoll | An atoll is a ring of coral rock, or a group of coral islands surrounding a lagoon. a coral island in the shape of a ring (atolu). Coral reef enclosing a lagoon. Atolls consist of ribbons of reef that may not be circular but that are closed shapes, sometimes miles across, around a lagoon that may be 160 ft (50 m) deep or more. Most of the reef itself is usually below the water surface; around the rim along the top are usually low, flat islands or more continuous strips of low, flat land | en |
| atoll | coral reef surrounding a lagoon isim | en |
| atoll | A horseshoe or circular array of islands, capping a coral reef system perched around an oceanic volcanic seamount (Levinton 1982) | en |
| atoll | A coral island consisting of a ring of coral surrounding a central lagoon Atolls are common in the Indian and Pacific Oceans | en |
| atoll | a horseshoe or circular array of islands, capping a coral reef system perched around an oceanic volcanic seamount | en |
| atoll | Coral reefs sometimes grow around seamounts that rise above the surface of the ocean As the seamount sinks or its peak erodes, the seamount will disappear beneath the water leaving the coral ring | en |
| atoll | A massive coral growth on a submerged mountain range or volcano, common in the Indian and Pacific Oceans The only English word derived from the Maldivian language, an atoll is a large coral reef, containing low inhabitable islands, encircling a sea water lagoon | en |
| atolls | plural of atoll | en |