Definition [Oxford Dictionary]: Fall suddenly and uncontrollably. Suffer a rapid decrease in value.[骤然下跌，（价值）猛跌]

His weight began to plunge.

他的体重开始骤然下降。

Japan's banks are in trouble because of bad loans and the stock market plunge.

日本各家银行处于困境，缘于不良贷款以及股市的暴跌。

Definition [Oxford Dictionary]: Undergo a sudden severe or prolonged fall in price, value, or amount. [（价格、价值等）暴跌]

Net profits slumped by 25%.

净利润暴跌了25%。

Land prices slumped.

地价大幅走低。

Definition [Oxford Dictionary]: Decrease rapidly in value or amount. [（数量、比率、价格）暴跌]

Her spirits plummeted at the thought of meeting him again.

一想到又要见到他，她的心情便直往下沉。

Hardware sales plummeted.

硬件销售量陡然下降。