flood plain

or floodplain

noun

1. a nearly flat plain along the course of a stream or river that is naturally subject to flooding.

flood plain

noun

1. the flat area bordering a river, composed of sediment deposited during flooding

Word History and Origins

Origin of flood plain¹

First recorded in 1870–75

Example Sentences

At Little Falls, Minn., flood-plain, deposits of sand and gravel are found to contain many artificial objects of quartz.

From Project Gutenberg

Those using the slough are almost certainly permanent inhabitants of the river flood plain.

From Project Gutenberg

In times of flood they are carried far away from the regular channel and spread over the wide flood-plain of the river.

From Project Gutenberg

The extension seaward of this flood plain forms the broad delta at the river's mouth.

From Project Gutenberg

Along its lower course “the flood plain is bordered by high bluffs of yellow sandstone.”

From Project Gutenberg