La*goon" (?), n. [It. or Sp. laguna, L. lacuna ditch, pool, pond,lacus lake. See Lake, and cf. Lacuna.] [Written also lagune.]

1.

A shallow sound, channel, pond, or lake, especially one into which the sea flows; as, the lagoons of Venice.

2.

A lake in a coral island, often occupying a large portion of its area, and usually communicating with the sea. See Atoll.

Lagoon island, a coral island consisting of a narrow reef encircling a lagoon.

 

© Webster 1913.