<p><strong>Noun</strong></p><ul><li>a large mass of snow, ice, etc., detached from a mountain slope and sliding or falling suddenly downward.</li><li>anything like an avalanche in suddenness and overwhelming quantity: an avalanche of misfortunes; an avalanche of fan mail.</li><li>Also called Townsend avalanche.</li><li>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.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object) av·a·lanched, av·a·lanch·ing: to come down in, or like, an avalanche.</li><li>(used with object) av·a·lanched, av·a·lanch·ing: to overwhelm with an extremely large amount of anything; swamp.</li></ul>