A slot (plural slots) is a narrow depression, notch, slit, or aperture. A slot may be used for receiving a coin or letter, or for admitting a person or animal into a building. It may also refer to an interior opening in a copy desk, occupied by the chief copy editor. In linguistics, a slot is a position within a construction into which any one of a set of morphemes or morpheme sequences can fit. Compare filler (def 5).
A slot machine is a gambling device that accepts cash or, in “ticket-in, ticket-out” machines, paper tickets with barcodes. The machine displays a series of reels and pays out credits based on the symbols on each line, as determined by its pay table. A player can adjust the number of coins or bills inserted into the machine by pressing a button or lever (either physical or on a touchscreen). Modern slot machines use random number generators to generate combinations of symbols, and many have a theme. In addition to the pay table, many slot machines also display other information on the screen, such as remaining jackpot amounts and total winnings.