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

Federal officials on Thursday extended the public comment period for a study evaluating whether portions of the Los Angeles coastline, including popular beaches in Santa Monica and Venice, could be designated as part of the National Park System. —City News Service, Daily News, 10 Apr. 2026

Taormina is a hilltop town on Sicily’s east coast, known for its ancient Greek theater and dramatic coastline. —Lauren Schuster, Miami Herald, 10 Apr. 2026

Again, the timeless beauty of the Connecticut coastline adds to the film’s power. —Christopher Arnott, Hartford Courant, 9 Apr. 2026

This flexibility enables the system to support amphibious operations and specialized missions along Ukraine’s coastlines and inland waterways. —Atharva Gosavi, Interesting Engineering, 9 Apr. 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
• byline
• canine

Kids Definition

coastline

noun

coast·​line ˈkōst-ˌlīn 

: the outline or shape of a coast