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

To build along its shore is less an act of display than one of respect, especially on a coastline where only about 1% of the land is developable. — Spencer Elliott, Forbes.com, 10 July 2026

This message appeared to fail to reach many families already seated along the coastline for the fireworks show, as a USA TODAY reporter witnessed folks trying to find an alternative route home after the event. — Noe Padilla, USA Today, 10 July 2026

Where to go From mountains to coastline, Georgia offers a variety of unique habitats for birds. — Lesly Gregory, AJC.com, 9 July 2026

For travelers looking to relocate to East Asia, the island nation of Taiwan stands apart for its diverse array of bustling night markets, verdant national parks, and tropical coastline. — Brittany Chang, Condé Nast Traveler, 9 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