noun - A lagoon is a shallow body of water separated from a larger body of water by barrier islands or reefs. Lagoons are commonly divided into coastal lagoons and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. Lagoons are common coastal features around the world and are shallow, often elongated bodies of water separated from a larger body of water by a shallow or exposed shoal, coral reef, or similar feature.
In Latin America often the use of laguna which lagoon translates to, is used to describe a lake. In Portuguese, lagoa may be a body of shallow sea water, but also a relatively small freshwater lake not linked to the sea.
Lagoon is derived from the Italian laguna, which refers to the waters around Venice, the Lagoon of Venice. Laguna is attested in English by at least 1612, and had been Anglicized to lagune by 1673. In 1697 William Dampier referred to a Lagune or Lake of Salt water on the coast of Mexico. Captain James Cook described an island "of Oval form with a Lagoon in the middle" in 1769.