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

By Tuesday and Wednesday, highs could be near or possibly exceed 80 degrees away from the coastline. —Matthew Villafane, CBS News, 29 Mar. 2026

With views of the Pacific Ocean and access to abundant wildlife, Nekajui is a Venn diagram of the natural bounty and diverse beauty that has long drawn travelers to the country's northwestern coastline. —Laura Dannen Redman, Condé Nast Traveler, 28 Mar. 2026

But increasingly, vessels are taking a different route, to the north around Larak Island, placing them in Iran’s territorial waters and closer to the Iranian coastline. —David McHugh, Chicago Tribune, 27 Mar. 2026

The fishery protects more than 145 acres of mangrove forest along its section of coastline. —Ryan Kellman, NPR, 27 Mar. 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