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

The coroner’s office confirmed those remains were also human, and a cadaver dog from the Los Angeles County Sheriff’s Department was deployed to search the surrounding coastline. —Stepheny Price, FOXNews.com, 5 Nov. 2025

Drivers can take two scenic routes to Arraial do Cabo—either the northern road that winds through rolling hills or the southern one that follows the coastline. —Aaron Randolph, Travel + Leisure, 5 Nov. 2025

What To Know The USGS earthquake monitoring map recorded four seismic events along Indonesia's coastline on November 4 and 5. —Hollie Silverman, MSNBC Newsweek, 5 Nov. 2025

And in mangrove regions, early tests show 97% accuracy—cutting processing time in half and helping governments act faster to protect fragile coastlines. —Sharon Goldman, Fortune, 4 Nov. 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