redouble
/ˌri:ˈdʌbl; ri`dʌbl/ v[I, Tn]
1 (cause sth to) become greater, stronger, more intense, etc （使某事物）变得更大、 更强、 再加倍
Her zeal redoubled. 她热情倍增.
We must redouble our efforts. 我们应该加倍努力.
2 (in the card-game of bridge) double again (a bid already doubled by an opponent) （桥牌中）将（对方已加倍的叫牌）再加倍.