Collins Chinese Dictionary Plus (3rd edition), 2011:
plunge [plʌndʒ]
I n
[c]
1
(=fall)
[of person] 跳入 tiàorù
[of person] 跳入 tiàorù
2
[in prices, rates] 猛跌 měngdiē
II vt
1
▶ to plunge sth into sth [+ knife, hand etc] 把某物猛插入另一物 bǎ mǒuwù měng chārù lìng yī wù
2
▶ to be plunged into darkness/chaos 陷入黑暗/混乱(亂) xiànrù hēi'àn/hùnluàn
III vi
1
▶ to plunge into sth (=fall) 撞入某处(處) zhuàngrù mǒuchù
(=leap) 跳入某处(處) tiàorù mǒuchù
(=leap) 跳入某处(處) tiàorù mǒuchù
2
[economy, interest rates] ▶ to plunge (to sth) 猛然跌入(某状(狀)态(態)) měngrán diērù (mǒu zhuàngtài)
3
[bird] 俯冲(衝) fǔchōng
- to take the plunge
(fig) 采(採)取断(斷)然行动(動) cǎiqǔ duànrán xíngdòng
- to plunge (o.s.)/be plunged into sth
(=become involved) 全身心投入某事 quán shēnxīn tóurù mǒushì