—n. 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. 3. Also called Townsend avalanche.Physics,Chem.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.
—v.i. to come down in, or like, an avalanche.
—v.t. to overwhelm with an extremely large amount of anything; swamp.