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

What to Know The NWS has issued multiple heat advisories, excessive-heat warnings and flash-flood alerts across the Central U.S. and parts of the Southeast coastline, many of which are in place until mid-week. —Mandy Taheri, MSNBC Newsweek, 19 July 2025

Amidst the larger-than-life developments of other coastlines, the properties here are tiny in comparison. —Carley Rojas Ávila, Forbes.com, 18 July 2025

In 2024, California was ranked the second-best state for hiking in United States by GB The Green Brand for its stunning coastlines, dense forests and rugged mountain ranges. —Sacbee.com, 14 July 2025

Much of El Camino Real runs parallel to California’s coastline, and some of the state’s finest beaches are just a short drive off the main route. —Cu Fleshman, Travel + Leisure, 12 July 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