A narrow, elongated depression or groove, notch, or slit. A narrow opening for receiving or admitting something, such as a coin or a letter. (journalism) The interior opening in a semicircular copy desk, usually occupied by the supervisor of the copy editors.

In the world of casino gaming, Slot is a machine that accepts cash or paper tickets with barcodes (in “ticket-in, ticket-out” machines) and then spins reels to display symbols. When the symbols line up, the player earns credits according to the paytable. Most slot games have a theme and the symbols and bonus features are aligned with that theme.

Symbols may also be weighted, such that a certain symbol appears more often on a particular reel than others. This can affect jackpot sizes and payback percentages. The microprocessors inside modern slot machines can program these variables, and they are often hidden from the players.

An airport slot gives an airline permission to operate at a congested airport during a specific time period. Using slots can help reduce delay times and fuel burn, but the cost of buying and maintaining them is high. In the long term, they are expected to be replaced by automated systems that are more scalable and less expensive. In the meantime, airports can use the slots they have now to accommodate more flights and reduce congestion.