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atoll

American  
[at-awl, -ol, -ohl, uh-tawl, uh-tol, uh-tohl] / ˈæt ɔl, -ɒl, -oʊl, əˈtɔl, əˈtɒl, əˈtoʊl /

noun

  1. a ring-shaped coral reef or a string of closely spaced small coral islands, enclosing or nearly enclosing a shallow lagoon.


atoll British  
/ əˈtɒl, ˈætɒl /

noun

  1. a circular coral reef or string of coral islands surrounding a lagoon

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of atoll

First recorded in 1615–25; earlier atollon, from French: a word used in early descriptions of the Maldive Island atolls; said to be Divehi ( Indo-Aryan language of the Maldives) atoḷu

Explanation

An atoll is an island formed by a ring-shaped coral reef encircling a lagoon. The word comes from the language of the Maldives, an island chain in the Indian Ocean famous for gorgeous beaches and coral reefs. The word atoll appeared in English in the early 17th century, when the British and the Dutch were vying for control of Indian Ocean trade. You may have heard of Bikini Atoll, in the South Pacific — where the U.S. did extensive nuclear testing in the 1940s and 1950s. Its people were moved to neighboring atolls but haven’t been able to return because of lingering radiation. Even so, Bikini Atoll has become a destination for divers interested in WWII shipwrecks.

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Vocabulary lists containing atoll

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The rescue spacecraft developed by the US startup Katalyst is slated to lift off Tuesday at 1023 GMT from a Pacific Ocean atoll aboard a small rocket named Pegasus.

From Barron's • Jun. 30, 2026

A single atoll in the Seychelles serves as home to hundreds of thousands of tortoises, while millions of flamingoes flock annually to Lake Natron in Tanzania.

From The Wall Street Journal • Jun. 19, 2026

The first body of an Italian diver, who was a member of the group, was recovered shortly after Thursday's accident near Vaavu atoll.

From BBC • May 19, 2026

The operation concerned a 50-mile-wide atoll, Rongelap Island, in the Marshall Islands.

From Slate • Jul. 22, 2025

On the second day his company was assembled on the top deck and told that they were moving toward Tarawa atoll, where they would go ashore at Betio, a strongly defended island.

From "Snow Falling on Cedars: A Novel" by David Guterson

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