ETYM French avalanche, from avaler to descend, to let down, from aval down, downward; from Latin ad + val, Latin vallis, valley. Related to Valley.
1. A slide of large masses of snow and ice and mud down a mountain.
2. A sudden appearance of an overwhelming number of things.
In World War II, code name for the Allied landings at Salerno, Italy, Sept 1943.
Fall of a mass of snow and ice down a steep slope. Avalanches occur because of the unstable nature of snow masses in mountain areas.
Changes of temperature, sudden sound, or earth-borne vibrations may trigger an avalanche, particularly on slopes of more than 35ş. The snow compacts into ice as it moves, and rocks may be carried along, adding to the damage caused.
Avalanches are particularly hazardous in ski resort areas such as the French Alps. In 1991 a massive avalanche considerably altered the shape of Mount Cook in New Zealand.
To tumble or cascade down a mountain side; said of snow masses in the mountains; SYN. roll down.