redouble

fe’l verb

1. To double, especially to double again; to increase considerably; to multiply; to intensify. Having lost sight of our objectives, we redoubled our efforts.
2. To double an opponent's doubling bid.
3. To become twice as big.
4. To double again what was reduced to a single state.

ot noun

1. An optional bid made by the side currently holding the highest bid for the contract, after the opposing side has doubled.