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

The homes, mostly clad in wooden exteriors, none more than two stories high, are scattered along 10 miles of coastline about 100 miles north of San Francisco. — Christopher Reynolds, Los Angeles Times, 24 Sep. 2026

In the Northeast, visitors discover a corridor where centuries of history, untamed coastlines, and cosmopolitan energy intertwine. — Condé Nast, Condé Nast Traveler, 23 Sep. 2026

The Maldives is the next coastline for UAE real estate developer Mohamed Alabbar, who signed an agreement with the archipelago’s government for a $12 billion waterfront and marina development near the capital Malé. — Kelsey Warner, semafor.com, 22 Sep. 2026

The Houthis have already seized a long stretch of the Yemeni coastline adjacent to the Red Sea – one of the world’s most important waterways – and control the Bab al-Mandeb chokepoint at its southern end. — Tim Lister, CNN Money, 21 Sep. 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