with obj.
1- make much greater, more intense, or more numerous使再加倍, 使更强, 使数量倍增：
we will redouble our efforts to reform agricultural policy.
我们将加倍努力, 改革农业政策。
1.1
- no obj. become greater or more intense or numerous变得更大（或更强、更多）：
pressure to solve the problem has redoubled.
要求解决问题的压力倍增。
1.2
- no obj. Bridge double a bid already doubled by an opponent【桥牌】对方加倍后再加倍。
- Bridge a call that doubles a bid already doubled by an opponent【桥牌】再加倍。
词源
late Middle English: from French redoubler, from re- 'again' + doubler 'to double'. The noun dates from the early 20th cent.