A narrow notch, groove or opening, such as a keyway in machinery or a slit for a coin in a vending machine. Also: a position in a group, series or sequence; an assignment or job opening.

A slot is a specific kind of casino game that allows players to win credits by spinning the reels and matching symbols. Modern slot games have evolved to meet the challenges of technology and changing tastes, but their basic mechanics remain the same. While minimalist titles still exist for the purists, most online casinos offer libraries of immersive slots with a variety of themes and features.

The term slot entered the English lexicon via a 19th-century variant of poker where players contributed an ante prior to the deal and a hand with a pair of jacks or better opened bidding. Its meaning broadened to encompass other types of gambling, particularly games where winnings accumulate over time but aren’t entirely determined by chance, such as keno or slot machines.

The first slot machine was invented in 1894 by Charles Fey, a mechanic from Bavaria who worked at a saloon in San Francisco. His three-reel machine, called the Card Bell, used a handle that activated the rotating reels, which carried playing card suitmarks that lined up to form poker hands. The reels were adorned with fruit and other images that suggested chewing gum dispensers in an effort to circumvent legal restrictions against gambling. This ploy proved successful, and the Mills Novelty Company soon introduced a version of its own machine with themed symbols.