A narrow notch or groove, especially one for receiving something, such as a keyway in a machine, or a slit for a coin in a vending machine. Also: A position in a group, series, or sequence, such as the last slot in a class or the last berth in an airplane.

1. A space or opening in a machine for inserting coins or paper tickets with barcodes, to activate a reel mechanism and allow a player to win credits based on the pay table displayed on the screen of the machine. In some machines, a “ticket-in ticket-out” system allows a player to redeem cash for credits at a separate redemption terminal. 2. A place or position, such as the seat in an airplane or the slot on a crowded stage, that has been assigned to someone: He was sitting in the slot for a guest speaker.

3. A position or time allocated for an aircraft to take off or land, as authorized by a civil aviation authority: The airline has been granted 40 more slots at U.S. airports.

4. The track or trail of a deer, as followed by its scent or by the marks it leaves on the ground: She was following the tracks of the buck through the woods. Also: The path or way a deer takes between the face-off circles on an ice hockey rink.

5. In computing, a position in memory or on a disk that can be reserved for holding a particular type of data: The program has four save slots.

6. In a slot machine, the area on the face of the machine that displays a combination of symbols, or payout values if they match: The win line is indicated by a vertical line through the reel window. The pay tables, which display how many matching symbols are needed to win and their payout value, are listed above and below the reel window or inside the game menu on video slot machines.

7. In journalism, the job or position of chief copy editor: He had been in the slot at the Gazette for 20 years.

The first of these was Charles Fey’s 1887 incarnation, which used three reels and allowed multiple pay lines, replacing the poker symbols with spades, horseshoes, hearts, and liberty bells. His invention was so successful that it led to a flurry of copycat machines. In a modern slot machine, microprocessors allow each symbol to be assigned a different probability of landing. The pay tables indicate the payouts for matching combinations, and some have bonus features that can be triggered by spinning a certain combination of symbols on the reels. A player can also use a Bet Max button to bet the maximum amount possible. This is usually displayed on the machine’s screen, along with a message that indicates when the player has reached this limit. The machine will then reset to the minimum bet. During this reset process, any credits earned will be reverted to their original value, and the machine will display “RESET” on the screen.