A narrow notch, groove, or opening, as in a keyway in a piece of machinery or a slit for coins in a vending machine. Also: a position in a group, series, sequence, etc.
A slot machine is a machine that pays out winning combinations of symbols on its reels. A player inserts cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode, into the slot and activates it by pushing a lever or button (either physical or on a touchscreen). The reels then spin and stop to rearrange the symbols and award credits according to the paytable. Most slot games have a theme and bonus features aligned with that theme. Classic symbols include fruit, bells, and stylized lucky sevens.
There are some players who swear that winning at slots is all about hitting the spin button twice as soon as you see a potential win. But they’re wrong. It’s true that the second hit on the spin button might help you take home more money, but it won’t change the fact that the result of a spin is decided by an RNG chip as soon as you press the spin button.