A slit, hole, or narrow opening, such as a keyway in machinery or a slot for a coin on a machine. Also, a position in a group, series, or sequence.

a slot in a machine that accepts paper money or paper tickets for a video game.

In computing, a slot is a dynamic placeholder that either waits for content (a passive slot) or calls out to it (an active slot). It can be used to hold either a container or an array of items. Slots work together with scenarios and renderers to deliver dynamic content on a Web page.

The term slots is also used in aviation to refer to an authorization for a plane to take off or land at a specific airport on a particular day during a specified time period. This authorization is distinct from air traffic control clearance and helps avoid repeated delays caused by too many flights attempting to take off or land at the same time.

When playing slots, a smart strategy is to look for machines that have recently paid out. The amount of the cashout will be displayed on the machine along with the number of credits left in the machine. If the numbers are very close, this is an indication that the slot has a high chance of paying out again soon. Also, a lot of casinos prefer to place the machines that pay well at the ends of their aisles so other customers will see them and want to play them as well.