A narrow elongated depression, groove, notch, or other small opening for receiving something, especially a coin or letter. Also: an assigned time or place for a plane to take off or land, granted by an airport coordinator in order to limit the number of flights at highly congested airports and prevent repeated delays that occur when too many aircraft try to take off or land at the same time. Also: the interior position on a copy desk, usually occupied by the chief copy editor.

In casino gaming, a slot is a line on which symbols are displayed. Some slot machines allow players to choose how many paylines they wish to wager on during a spin, while others have a fixed amount of paylines and require the player to play all available lines. The latter are often referred to as ‘fixed slots’.

A slot is an element that acts as a dynamic placeholder that either waits for content to be added (a passive slot) or calls for it using a scenario (an active one). It can point to a repository item that contains content, or to a renderer that specifies how to present the content. Almost all desktop computers come with expansion slots, which are places for add-on circuitry that provides specialized capability, such as video acceleration or disk drive control. In sports, a slot receiver is a wide receiver who is typically shorter and faster than traditional wide receivers and thus poses more risk of being injured during big hits.