barrier island

American  

noun

1. a broadened barrier beach, habitable in places, that provides a measure of protection for the mainland, as during hurricanes and tidal waves.

---

barrier island Scientific  

/ băr′ē-ər /

1. A long, narrow sand island that is parallel to the mainland and serves to protect the coast from erosion. Barrier islands typically have dunes along the exposed outer side, zones of vegetation in the interior, and swampy areas along the inner lagoon.

---

barrier island Cultural  

1. Any low sandy island that is parallel to the mainland and protects it from storms. (See Cape Hatteras.)

---

Discover More

Barrier islands normally change location every ten to thirty years, a fact that makes coastline management a major problem in environmental policy.

Example Sentences

Officials for St. Paul’s Fire District, which covers Charleston County, said Edisto Island, the barrier island where the home is located, has a limited water supply, which made fighting the fire more difficult.

From The Wall Street Journal • Oct. 6, 2025

Located on a barrier island between Lake Worth Lagoon and the Atlantic Ocean in South Florida, the club’s landscaping could place it anywhere in the United States.

From Salon • Aug. 23, 2025

Hurricane Milton made landfall near Siesta Key — a barrier island near Sarasota — around 8:30 p.m.

From Los Angeles Times • Oct. 10, 2024

Areas associated with little to no damage were spatially clustered in the southern and central portion of the island, with most structures concentrated on the landward side of the barrier island.

From Science Daily • Apr. 29, 2024

Off the southeastern coast of Iceland sits a low barrier island called Papos.

From "Into the Wild" by Jon Krakauer