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

Redwood includes old-growth redwood groves, open prairie, miles of California coastline, and two rivers. —Patricia Doherty, Travel + Leisure, 3 May 2026

Compared to other regions in the country, Dubrovnik could be harder hit if the fuel crisis deepens because of its location at the southern tip of Croatia’s Adriatic Sea coastline. —Darko Bandic, Fortune, 2 May 2026

More than 10,000 Marines from expeditionary units are now in theater, giving Trump the option to launch limited ground operations, such as seizing a small stretch of coastline or initiating an assault on Kharg Island, the hub of Iran’s oil industry. —Los Angeles Times, 2 May 2026

Even though a widespread rain event is no longer likely, areas along the immediate coastline may see a stray shower or two. —Matthew Villafane, CBS News, 2 May 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