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

Yanbu is located on the Red Sea and Jazan province has a coastline on the same sea. — CNN Money, 25 July 2026

Even so, the building’s location on the coastline, and so close to the fault systems, put them at risk. — Syra Ortiz-Blanes, Miami Herald, 24 July 2026

Aljezur The Algarve is Portugal’s southernmost region—its coastline less than 150 miles from the northern tip of Morocco—and the region has a long history of North African influence. — Katie Silcox, Vogue, 24 July 2026

Artificial reefs, on the other hand, are created by humans from any number of materials from rocks to sunken ships to protect coastlines or attract aquatic life. — Laura Horne, Charlotte Observer, 23 July 2026

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
• brucine
• byline

Kids Definition

coastline

noun

coast·​line ˈkōst-ˌlīn 

: the outline or shape of a coast