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

It is bordered on one side by a strip of Iranian coastline. —Bart Jansen, USA Today, 13 June 2026

One woman is dead and another is in critical condition after they were swept out to sea by a powerful tide in Santa Cruz this week amid hazardous ocean conditions that forecasters warn will continue across the California coastline this weekend, authorities said. —Clara Harter, Los Angeles Times, 13 June 2026

Alternatively, visitors can get out on the water by swimming, surfing, paddleboarding, or kayaking along the island’s rugged coastline. —Lauren Dana Ellman, Travel + Leisure, 13 June 2026

Part of two continents, Egypt has coastlines along the Mediterranean Sea, Red Sea, and the Gulf of Aqaba. —Michael Goldstein, Forbes.com, 12 June 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