lagoon
Americannoun
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an area of shallow water separated from the sea by low sandy dunes.
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Also lagune any small, pondlike body of water, especially one connected with a larger body of water.
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an artificial pool for storage and treatment of polluted or excessively hot sewage, industrial waste, etc.
noun
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a body of water cut off from the open sea by coral reefs or sand bars
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any small body of water, esp one adjoining a larger one
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A shallow body of salt water close to the sea but separated from it by a narrow strip of land, such as a barrier island, or by a coral reef.
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A shallow pond or lake close to a larger lake or river but separated from it by a barrier such as a levee.
Other Word Forms
- lagoonal adjective
Etymology
Origin of lagoon
1605–15; earlier laguna (singular), lagune (plural) < Italian < Latin lacūna (singular), lacūnae (plural) “ditch, pool,” akin to lacus basin, lake 1; lacuna
Explanation
If you are snorkeling off the coast of Florida in water cut off from the main ocean, you are likely in a lagoon — a body of water separated from the main ocean. If you’re familiar with the 60s TV show “Gilligan’s Island,” you probably already know what a lagoon is. Much of the show’s action took place at the lagoon, where the lovable castaways spent their time hanging around and planning how to be rescued. A lagoon is a good place for castaways to congregate because it’s shallow and separated from the ocean by a natural barrier, which means it’s protected from the rough waters of the ocean and offers easier access for swimming and fishing. If you’re ever stranded on a deserted island, you too would probably choose to spend your time at the lagoon, staring into the distance and watching for approaching ships.
Vocabulary lists containing lagoon
Physical Geography - Introductory
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Physical Geography - Middle School
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Physical Geography - High School
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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.
"Where they plan to expand the port is a particularly bio-sensitive hotspot," Namcob's Neil Shaw says from his windswept office near a lagoon where flamingos feed.
From BBC • Mar. 11, 2026
The crescent-shaped Venetian lagoon glows in shades of turquoise, revealing the network of islands that form the floating city of Venice along the Adriatic coast.
From Science Daily • Feb. 9, 2026
Weeks before the Makoko demolition, bulldozers levelled dozens of houses in the Oworonshoki neighbourhood on the opposite side of the lagoon.
From Barron's • Jan. 16, 2026
“When we started going, there would be 400 adult whales in the lagoon, including 100 moms and their babies,” he told me.
From Los Angeles Times • Jan. 8, 2026
The fair’s engineers conducted the first test twelve feet from the lagoon on ground intended to support the northeast corner of the Electricity Building.
From "The Devil in the White City" by Erik Larson
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.