Atoll

مترادف و متضاد atoll

1. noun A coral island or series of coral islands forming a ring that nearly or entirely encloses a shallow lagoon. Atolls are surrounded by deep ocean water and range in diameter from about 1 km (0.62 mi) to over 100 km (62 mi). They are especially common in the western and central Pacific Ocean and are believed to form along the fringes of underwater volcanoes.
   Synonyms: island, isle, reef