avalanche
/ˈævəˌlæn(t)ʃ/
noun
A mass of snow, ice, and rocks falling rapidly down a mountainside.
he was swept to his death by an avalanche in 1988
snowslide,snow slip
intransitive verb
(of a mass of snow, ice, and rocks) descend rapidly down a mountainside.
The snow had recently avalanched, so only surface hoar is thawing.