[I,T always + adv / prep] to move, fall, or be thrown suddenly forwards or downwards

（使）突然向前倒下（跌落）:

Her car swerved and plunged off the cliff.

她的车突然转向冲下了悬崖。

Both the climbers had plunged to their deaths .

两位攀登者都坠地身亡。

[I] if a price, rate etc plunges, it suddenly decreases by a large amount

〔价格、比率等〕暴跌，骤降:

The unemployment rate plunged sharply.

失业率骤降。

Oil prices have plunged to a new low .

石油价格创了新低。

In the recession, the company's profits plunged 60%.

萧条时期，那家公司的利润骤跌了 60%。

[I] [literary] if a ship plunges, it moves violently up and down because of big waves

〔船〕猛烈地颠簸

take the plunge, to decide to do something important or risky, especially after thinking about it for a long time

〔尤指经过长时间思考之后〕决定奋力一搏，决定冒险一试:

We took the plunge and set up our own business.

我们毅然决定开创自己的事业。

[C] a sudden large decrease in the price, value etc of something

骤降:

a dramatic plunge in house prices

房价的暴跌

[C usually singular] a sudden movement down or forwards

突降; 俯冲:

The plane began a headlong plunge towards the Earth.

飞机开始向地面俯冲。

[C usually singular] when someone suddenly becomes involved in something new

突然卷入:

his sudden plunge into marriage

他的闪电结婚

[C usually singular] a jump or DIVE into water, or a quick swim

跳水;〔短时间的〕游泳:

a quick plunge in the lake

在湖中游一小会儿泳