lahar

American  

[lah-hahr] / ˈlɑ hɑr /

noun

Geology.

1. a landslide of wet volcanic debris on the side of a volcano.

2. the deposit left by such a landslide.

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lahar British  

/ ˈlɑːhɑː /

noun

1. a landslide of volcanic debris mixed with water down the sides of a volcano, usually precipitated by heavy rainfall

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lahar Scientific  

/ lä′här′ /

1. A wet mass of volcanic fragments flowing rapidly downhill. Lahars usually contain ash, breccia, and boulders mixed with rainwater or with river or lake water displaced by the lava flow associated with the volcano.

2. The deposit produced by such a flowing mass.

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Etymology

Origin of lahar

1925–30; < Javanese: lahar, lava

Example Sentences

They also warned of potential lahar floods - a type of mud or debris flow of volcanic materials - if heavy rain occurs.

From BBC • Jul. 8, 2025

The rains also triggered volcanic mudslides or lahar in villages surrounding Mount Mayon, an active volcano in Bicol.

From BBC • Oct. 24, 2024

What’s more likely to cause a threat in our lifetime is a volcano-related phenomenon called a lahar.

From Seattle Times • May 18, 2024

“At Mount Rainier, large lahars have been associated with eruptions like the Osceola Mudflow,” Westby says, referring to a lahar that happened at the volcano 5,600 years ago.

From Scientific American • Dec. 6, 2022

The water in Spirit Lake would stay put, but glacier melt and groundwater released from an eruption could create a fast-moving lahar.

From "Mountain of Fire" by Rebecca E. F. Barone