atoll

atoll

noun \ˈa-ˌtȯl, -ˌtäl, -ˌtōl, ˈā-\

Definition of ATOLL

: a coral island consisting of a reef surrounding a lagoon

Illustration of ATOLL

Origin of ATOLL

Divehi (Indo-Aryan language of the Maldive Islands) atolu

First Known Use: 1625

Other Geology Terms

anthracite, boulder, cwm, erratic, igneous, intrusive, mesa, sedimentary, silt, swale

Rhymes with ATOLL

Algol, austral, Bhopal, cabal, Cabral, cantal, Chagall, chorale, grand mal, gun moll, hamal, jacal, mistral, narwhal, Natal, nopal, Pascal, petrol, quetzal, Rampal, real, rial, riyal, Rizal, Shawwal, tical, timbale, Transvaal

atoll

noun    (Concise Encyclopedia)

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.