I always took it to mean something one team would do after the other team had doubled.
Indeed it is.
(Whatever that means in the context of bridge)
The first part of every hand of bridge consists of the players ‘bidding’ in turn - i.e. saying how many tricks they expect to make if their nominated suit is trumps. If your opponent makes a bid that you believe you can prevent them making, you have the option of saying “Double!” This means that if this bid is accepted, and they have to play that hand, they stand to make double the points if they succeed, and lose double the points if they fail. However, if they are really sure they can do it, they have the option of saying “Redouble!” which redoubles the stakes either way.