“Jackpot” is a uniquely American word. It can mean a big prize won for gambling or in a sweepstakes or lottery or simply be used as an interjection indicating an exciting discovery. It's also the name of a tiny town in Nevada, near the Idaho state line.
The term has its origins in 1880s slang. When poker players had a game going and no one had a pair of jacks or higher in his hand, the antes would be progressively higher for each hand, until someone came up with those jacks. When they did, they won the “jacks’ pot,” or jackpot. Like much American slang, the term caught on for its snappy, direct feel and was in wide use by the 1920s. At that time, it also became criminal slang for being arrested.
A gambling jackpot is usually the biggest prize in the game. In a progressive gambling situation, such as with slot machines, several machines are linked, with the prize increasing with every quarter or dollar the player feeds into the machine. If someone “hits” or comes up with the maximum combination, then he or she wins the money — whatever total the slot machine was showing at the time.
If someone hits a jackpot on the slots, he or she should never leave the machine before a casino attendant arrives. That’s essentially forfeiting that prize to anyone who happens along. Most slot machines have a light on top that flashes when an attendant is needed, but if no one shows up right away, the winner should ask the cocktail server to call an attendant — for a nice tip.
“Jackpot!” is also an interjection. It is usually said when someone discovers something after a long search and means “I found exactly what I was looking for.” The word can also be used to indicate a desired outcome for a scientific study such as, “When we found a gene that causes breast cancer, we knew we hit the jackpot.”
There is also a small town in northeast Nevada, about 1 mile (1.6 kilometers) from the Idaho state line, named Jackpot. Its population was 1,195 in the 2010 census. It is unincorporated, in spite of having four casinos, a post office, small airfield, golf course, and its own schools. U.S. Highway 93 runs through the middle of the community, which is some distance away from any other large town.
Americans are good at borrowing words from other languages and cultures, but “jackpot” is an original term.