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

Midway through the conversation, Šeregi disappears, to pop up five minutes later, this time on a speedboat with the coastline receding behind him. — Melanie Goodfellow, Deadline, 5 Nov. 2026

The coastline in San Diego and Orange counties is expected to be particularly toasty for November. — Terry Castleman, Los Angeles Times, 5 Nov. 2026

Torrential rain along Florida's central and eastern coastline and in some inland counties has flooded roads, led to school shutdowns in some counties, and prompted election officials to find alternative polling places in affected areas. — CBS News, 3 Nov. 2026

Torrential rain along Florida’s central eastern coastline and in some inland counties has flooded roads and led to the shutdown of schools in some counties, and election officials are attempting to find alternative polling places in affected areas. — Gray Rohrer, Miami Herald, 3 Nov. 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