[ 'avəlα:nʃ ]
■ noun
1》 a mass of snow, ice, and rocks falling rapidly down a mountainside.
2》 an occurrence of something in overwhelming quantities.
3》 Physics a cumulative process in which an ion or electron generates further ions or electrons by collision.
■ verb
1》 fall in an ~.
2》 Physics undergo a rapid increase in conductivity due to an ~ process.
Origin
C18: from Fr., alt. of Alpine dialect lavanche , influenced by avaler 'descend'.