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 ships were directed to take a route along the southern side of the Strait of Hormuz, hugging Oman's coastline, rather than a route along Iran's coastline on the northern side of the strait. — Jackie Northam, NPR, 17 July 2026

Layer a second destabilization vector onto that corridor, one rooted in Sudan's interior rather than Yemen's coastline, and the risk compounds in ways most boardrooms haven't modeled, even before this week's news. — Frank Ahrens, Forbes.com, 17 July 2026

State Parks Director Armando Quintero and conservation advocates said the expansion is a boost for public access and the long-term protection of the state’s coastline. — Ruben Vives, Los Angeles Times, 16 July 2026

Goldenvoice is bringing a new music festival to the Southern California coastline this fall. — Holly Alvarado, Daily News, 16 July 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