PLUNGE

[noun] [C]I really enjoyed my plunge (= jumping in and swimming) in the pool.There has been a plunge in the (value of the) dollar (= it has suddenly fallen in value by a large amount) today.We are expecting a plunge (= a large fall) in profits this year.To take the plunge is determinedly to make a decision to do something, esp. after thinking about it for a long time.I've decided to take the plunge and set up my own business.They're finally taking the plunge and getting married.