Slot is a continuous opening in a structure that has a specific grammatical function in tagmemics. The term also refers to a job opening, a trapdoor on a stage, a hollow tuck on a dress, or an interior opening in a copy desk. Its meanings vary depending on the context: a slot in a newspaper is an open job position for a chief copy editor, a slot in an airport is authorized by an air-traffic authority, and so on.

Slot machines accept cash or paper tickets with barcodes to enter the game, and the player activates them by pressing a lever or button. The reels then spin, and if winning combinations are created, the player receives credits according to the paytable. Different slot machines use different symbols, but they are usually characterized by familiar images. Fruits, bells, and stylized lucky sevens are classic symbols. Each slot machine also has a theme that influences the game.

Unlike outside receivers, Slot receivers typically line up a little bit in the backfield, a few steps away from the line of scrimmage. This gives them more options than outside receivers. They are also more flexible and agile.