Re: Double down?
> "double down" makes sense. You lose a bet, then place the same bet again... that's
> doubling down (probably soon to be "doubly" down).
AFAIK gamblers who double down (or double up), e.g. at the roulette wheel, usually don't last long; either they run out of money or they are "invited" to leave the casino and not come back.
There's a bet in Blackjack called double down, or doubling down. When dealt two cards totaling ten or eleven you may double your bet and you get one more "down card", i.e. a card dealt to you face down that nobody else can see. (For the card counters.) Often the odds are good to be dealt a ten or a face card and thus a good chance of either winning or tying with the dealer.