coastline

noun

coast·​line ˈkōs(t)-ˌlīn 

1

: a line that forms the boundary between the land and the ocean or a lake

2

: the outline of a coast

Examples of coastline in a Sentence

The plane flew along the eastern coastline.

Recent Examples on the Web

Visiting this part of the island isn’t for the faint of heart, with a rugged coastline, crashing waves and a truly wild expanse. —Nora Heston Tarte, Mercury News, 25 Dec. 2025

Alagoas While Bahia’s beaches steal the spotlight, the nearby state of Alagoas is a quiet rival, offering some of Brazil’s most idyllic coastline. —Paul Irvine, Travel + Leisure, 23 Dec. 2025

The Southern coastline is blessed with wild shrimp, and freshly caught, local wild shrimp is unlike any other, with a rich, plump, succulent flavor. —Alexandra Emanuelli, Southern Living, 22 Dec. 2025

The second starts in London, then traces Britain’s eastern coastline to Edinburgh, Scotland, before heading further north to Norway and Denmark. —Rachel Cormack, Robb Report, 22 Dec. 2025

Word History

First Known Use

1856, in the meaning defined at sense 1

Rhymes for coastline

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• byline
• canine

Kids Definition

coastline

noun

coast·​line ˈkōst-ˌlīn 

: the outline or shape of a coast