moraine

American  

[muh-reyn] / məˈreɪn /

noun

1. a ridge, mound, or irregular mass of unstratified glacial drift, chiefly boulders, gravel, sand, and clay.

2. a deposit of such material left on the ground by a glacier.

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moraine British  

/ mɒˈreɪn /

noun

1. a mass of debris, carried by glaciers and forming ridges and mounds when deposited

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moraine Scientific  

/ mə-rān′ /

1. A mass of till (boulders, pebbles, sand, and mud) deposited by a glacier, often in the form of a long ridge. Moraines typically form because of the plowing effect of a moving glacier, which causes it to pick up rock fragments and sediments as it moves, and because of the periodic melting of the ice, which causes the glacier to deposit these materials during warmer intervals.

2. ◆ A moraine deposited in front of a glacier is a terminal moraine.

3. ◆ A moraine deposited along the side of a glacier is a lateral moraine.

4. ◆ A moraine deposited down the middle of a glacier is a medial moraine. Medial moraines are actually the combined lateral moraines of two glaciers that have merged.

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moraine Cultural  

1. A pile of debris, often extending for miles, deposited by a glacier. It is composed of rock fragments transported by the ice, which are left behind when the ice melts.

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Other Word Forms

• morainal adjective
• morainic adjective

Etymology

Origin of moraine

First recorded in 1780–90; from French, from Savoyard dialect morêna “rise in the ground along the lower edge of a sloping field,” equivalent to mour(o) “mound, accumulation of earth” (from unattested murr- “mound, elevation,” apparently pre-Latin ) + -ena suffix of landforms, probably of pre-Latin origin; compare Upper Italian (Piedmont) morena “heap of organic detritus,” Spanish moreña “heap of stones, moraine”

Example Sentences

When part of its moraine slid into the lake a little after 10 p.m. on the night of Oct.

From The Wall Street Journal • Apr. 1, 2026

The cemetery rests, as well, on heights formed by the Ice Age terminal moraine, while the bedrock schist she imprinted dates even deeper in geological time.

From New York Times • Nov. 24, 2021

Riding the crest of a moraine created by the receding Easton Glacier, Railroad Grade is aptly named.

From Seattle Times • Oct. 3, 2021

In valley glaciers, moraine also includes material falling on the sides of the glacier by mass wasting from the valley walls.

From Textbooks • Jan. 1, 2017

Snow-fields stretched down from the pass into the valleys of moraine.

From "The Left Hand of Darkness" by Ursula K. Le Guin

Related Words

• hill
• rim