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

Newsom, no longer a candidate for public office in California, and perhaps speaking to a national audience, even threw some shade on an agency that’s widely viewed as having kept much of the state’s 840-mile coastline comparatively pristine for the past 50 years. —Andre Mouchard, Oc Register, 19 Apr. 2026

Authorities have stepped up maritime enforcement along the northern coastline in response to recurring arrivals. —ABC News, 17 Apr. 2026

Sharif is from Egypt and has spent decades working along this coastline. —Sohel Uddin, CBS News, 17 Apr. 2026

Both cities manage the same coastline and face the same if not smaller, maintenance demands. —Haylee Rea, San Diego Union-Tribune, 17 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