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

Under Iran’s approval procedure for vessels wanting to transit the strait, ships must take a different route than before the war — to the north, near Iran’s coastline. —Ben Finley, Chicago Tribune, 25 Apr. 2026

There’s also the La Jolla coastline, which includes La Jolla Shores and Torrey Pines State Beach, staffed by lifeguards year-round. —Kara Williams, USA Today, 25 Apr. 2026

Still, the past decade has seen a string of new-agey boutique hotels populating the seaside town’s western shores, signaling a new awakening for this slice of France’s western coastline. —Monica Mendal, Vogue, 24 Apr. 2026

Rising sea levels and climate change are continuing to impact and threaten our coastline right here in New York City. —Jessica Moore, CBS News, 24 Apr. 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