A narrow notch, groove, or opening, such as a keyway in machinery or a slot for a coin in a vending machine. Also, the position of chief copy editor on a newspaper staff. (journalism) The inside of the “rim” or semicircular copy desk, occupied by the supervisor of the copy editors. (slang) To put someone or something where it belongs. (see also slit and slot in)

A container for dynamic content on a Web page. A slot can either wait passively for content to be called upon or it can call a renderer to deliver the content. In a Web site built with the ACC, slots work in tandem with scenarios and renderers to manage the delivery of content to the page.

In probability theory, a slot is the number of ways an outcome can occur, and is thus the likelihood that the event will occur, given that it has already occurred once. For example, the probability of a coin toss landing heads up is 12, or 50%.

In a slot machine, a player inserts cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode, and then activates the machine by pressing a lever or button, which spins and stops the reels. The symbols are then displayed, and if they match a winning combination as listed on the pay table, the player earns credits according to that table. Symbols vary by machine, but classic symbols include spades, hearts, diamonds, horseshoes, and liberty bells.