the outline or contour of a coast; shoreline.
the land and water lying adjacent to a shoreline.

Origin of coastline

First recorded in 1855–60; coast + line1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for coastline

Contemporary Examples of coastline

Historical Examples of coastline

British Dictionary definitions for coastline



the outline of a coast, esp when seen from the sea, or the land adjacent to it
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for coastline

1860, from coast (n.) + line (n.).

Online Etymology Dictionary, © 2010 Douglas Harper