Meaning

noun a slide of large masses of snow and ice and mud down a mountain

noun a sudden appearance of an overwhelming number of things

verb gather into a huge mass and roll down a mountain, of snow

originFrom French avalanche, from Franco-Provençal (Savoy) avalançhe, blend of aval (“downhill”) and standard lavençhe, from Vulgar Latin *labanka (compare Occitan lavanca, Italian valanga), of uncertain origin, perhaps an alteration of Late Latin lābīna (“landslide”) (compare Franco-Provençal (Dauphiné) lavino, Romansh lavina), from Latin lābēs, from lābor (“to slip, slide”).

Etymology from Wiktionary, CC BY-SA 3.0