[ av-uh-lanch, -lahnch ]
See synonyms for avalanche on Thesaurus.com
  1. a large mass of snow, ice, etc., detached from a mountain slope and sliding or falling suddenly downward.

  2. anything like an avalanche in suddenness and overwhelming quantity: an avalanche of misfortunes; an avalanche of fan mail.

  1. Also called Townsend avalanche. Physics, Chemistry. a cumulative ionization process in which the ions and electrons of one generation undergo collisions that produce a greater number of ions and electrons in succeeding generations.

verb (used without object),av·a·lanched, av·a·lanch·ing.
  1. to come down in, or like, an avalanche.

verb (used with object),av·a·lanched, av·a·lanch·ing.
  1. to overwhelm with an extremely large amount of anything; swamp.

Origin of avalanche

1755–65; <French < dial. (Savoy) avalantse, alteration (by association with avaler to descend rapidly) of laventse<pre-Latin (perhaps Ligurian) *lavanca, or reshaping of Late Latin labīna landslide (derivative of Latin labī to slide) with a pre-Latin suffix -anca

Words that may be confused with avalanche

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Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use avalanche in a sentence

British Dictionary definitions for avalanche


/ (ˈævəˌlɑːntʃ) /

    • a fall of large masses of snow and ice down a mountain

    • a fall of rocks, sand, etc

  1. a sudden or overwhelming appearance of a large quantity of things: an avalanche of letters

  1. physics a group of ions or electrons produced by a single ion or electron as a result of a collision with some other form of matter

  1. to come down overwhelmingly (upon)

Origin of avalanche

C18: from French, by mistaken division from la valanche, from valanche, from (northwestern Alps) dialect lavantse; related to Old Provençal lavanca, of obscure origin

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

Scientific definitions for avalanche


[ ăvə-lănch′ ]

  1. The sudden fall or slide of a large mass of material down the side of a mountain. Avalanches may contain snow, ice, rock, soil, or a mixture of these materials. Avalanches can be triggered by changes in temperature, by sound vibrations, or by vibrations in the earth itself.

  2. A process resulting in the production of large numbers of ionized particles, in which electrons or ions collide with molecules, with each collision itself producing an additional electron or ion that in turn collides with other molecules. Avalanches are what generate the pulses of electric current that are registered by Geiger counters.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.