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

Those who make it to Santa Cruz after an hourlong ferry ride out of Ventura are rewarded with 77 miles of craggy coastline cliffs, vast sea caves and vibrant tide pools. —Paul Bersebach, Oc Register, 25 June 2025

Six million tons end up in our coastlines and rivers annually, much of it from everyday items like shampoo bottles, food packaging, and water bottles. —Dianne Plummer, Forbes.com, 20 June 2025

As summer approaches, a juvenile great white shark named Dold has today been detected off the Long Island coastline, marking the latest milestone in a months-long migration that has taken him up the U.S. East Coast. —Alice Gibbs, MSNBC Newsweek, 20 June 2025

The property off Highway 1 resembles your own private headlands park with unparalleled panoramic views of the sea arches and the coastline. —David Caraccio, Sacbee.com, 19 June 2025

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