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

Their roots knit the coastline together, sheltering marine life and fish and absorbing carbon emissions. — ABC News, 22 Oct. 2026

California has long prided itself as a regulatory trailblazer, whether to preserve its coastline, reduce air pollution, protect gig workers, ensure data privacy or battle climate change. — Los Angeles Times, 22 Oct. 2026

The good news is that its strongest winds and heaviest rain will remain over the Atlantic, with impacts along our coastline gradually diminishing. — Kate Bilo, CBS News, 22 Oct. 2026

Southern California’s fragile coastline is being transformed one storm at a time by record-setting king tides and storm surges. — David Hickey, NBC news, 21 Oct. 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