Lahar

A lahar is a type of mudflow composed of pyroclastic material and water that flows down from a volcano, typically along a river valley.The term 'lahar' originated in the Javanese language of Indonesia.Lahars have the consistency of concrete: fluid when moving, then solid when stopped. Lahars can be huge: the Osceola lahar produced 5,600 years ago by Mount Rainier in Washington produced a wall of mud deep in the White River canyon and extends over an area of over for a total volume of 2.3 cubic kilometers (0.55 cubic miles).
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Noun
1. an avalanche of volcanic water and mud down the slopes of a volcano
(hypernym) avalanche

n. lahar

[Mesopotamian] The Sumerian god of cattle and particularly of sheep. He was created by Enlil.

A flow of pyroclastic material mixed with water. A lahar is often produced when a snow-capped volcano erupts and hot pyroclastics melt a large amount of snow or ice.