A coral area or islands consisting of a belt of red coral reef partly submerged surrounding a central lagoon or depression a lagoon island
- an island comprising a circular red coral reef surrounding a lagoon
- A coral area or countries, consisting of a belt of red coral reef, partially submerged, surrounding a central lagoon or despair; a lagoon area.
1620s, atollon, from Malayam atolu "reef," probably from adal "closing, uniting." Popularized in current type by Darwin's writings.
(letter.) A coral area or countries, composed of a belt of red coral reef, partially submerged, surrounding a central lagoon or depression; a lagoon island.
Often, as has been said, the atoll is divided into a number of islets, but in some smaller atolls the ring is complete, and the sea-water gains access beneath the surface of the reef to the lagoon within, where it is sometimes seen to spout up at the rise of the tide.