Lagoon (noun)

1. A shallow body of salt or brackish water, separated from the sea by sandbars or coral reefs.
2. A small lake near the sea or in a marshy area.
3. An artificially created lake or pool.

Origin:

From italian 'laguna' which comes from latin 'lacuna' meaning 'small lake or pool'.

Examples:

1. The tropical island was surrounded by a clear blue lagoon.
2. The residents of the coastal town enjoy swimming in the lagoon on hot summer days.
3. The lagoon is home to a diverse array of plant and animal species.
4. The construction of the lagoon involved creating a large pool for recreational activities.
5. The guests at the resort can enjoy a relaxing dip in the lagoon-style pool.