A jackpot is any large amount of money won through gambling.
The word comes from a game of draw poker in which only a player dealt a pair of jacks or better can open.
Several hands are usually dealt before this happens, and with each deal the players must add to the ante, which can grow to a considerable amount of money, the “jack” pot.
When two jacks are finally dealt and a player opens the betting, the winner will take the jackpot.
A lottery winning called a “jackpot”, and is commonly used for a large winning.