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

This area has been known for tuna fishing for thousands of years, with fisherman dwellings surviving along this stretch of coastline from the 1600s. — Megan Rose Murray, Condé Nast Traveler, 22 Aug. 2026

Sam would draw a map, sketching out the coastline of the Levant and marking a dot. — Rozina Ali, New Yorker, 21 Aug. 2026

That matters because the greatest damage is not confined to the coastline or the center of the forecast cone. — Monica Sanders, Forbes.com, 20 Aug. 2026

There are no roads linking communities along the more than 650 kilometers (406 miles) of Choco's coastline hugging the Pacific Ocean to the interior. — ABC News, 19 Aug. 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