Definition

1. Noun:
   • A ring-shaped coral reef, island, or series of islets surrounding a central lagoon: An atoll is a specific type of island formed by coral growth on the rim of a submerged volcano, creating a circular or horseshoe-shaped structure with a lagoon in the center.

Examples of Usage

• Noun:
  • The Maldives is a nation composed of numerous coral atolls.
  • Scientists study the unique ecosystem within the atoll's lagoon.
  • The plane flew over a remote atoll in the Pacific Ocean.

Advanced Usage

• Geological Formation: In geology and geography, 'atoll' specifically describes the final stage in the development of a volcanic island, where the central landmass has subsided, leaving only the coral reef ring.
  • The atoll is a classic example of Darwin's theory of coral reef formation.

Variants and Related Words

• Lagoon (n): The shallow, often calm body of water enclosed by an atoll's reef.
  • The crystal-clear lagoon was perfect for snorkeling.
• Coral Reef (n): The underlying structure, made from coral polyps, that forms the atoll.
  • The health of the coral reef is vital to the atoll's existence.

Synonyms

• Coral island: A more general term for an island formed primarily from coral.
• Reef island: An island whose foundation is a coral reef.

Related Phrases

• Atoll formation: The geological process by which an atoll is created.
  • The documentary explained the slow process of atoll formation over millennia.
• Atoll nation: A country whose territory consists primarily of atolls.
  • Kiribati is an atoll nation vulnerable to rising sea levels.

Noun

1. an island consisting of a circular coral reef surrounding a lagoon