n.[U][C]

1. 动乱；动荡；骚乱；激变；剧变
   Mass unemployment may lead to social upheaval.

   大批失业会导致社会动乱。

   The death of the King caused political upheaval in the country.

   国王逝世造成政局的动荡。

2. 胀起；鼓起；举起；（地壳）隆起

n.

1. a violent or sudden change or disruption.
2. an upward displacement of part of the earth's crust.