ATOLL


Meaning of ATOLL in English

n.

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.

Britannica Concise Encyclopedia.      Краткая энциклопедия Британика.