A narrow depression, notch, or other narrow opening, especially one for receiving something, such as a coin or a letter. See also hole, slit, vent, and aperture. Also, a period of time in a sequence or schedule: He booked his haircut for the 2 p.m. slot. Linguistics: A position within a construction into which any one of a set of morphemes or morpheme sequences can fit. The word slot is also used figuratively: He slotted the book into the shelf.

In a casino slot machine, the reels are emblazoned with symbols that pay out prizes according to combinations. Charles Fey’s 1895 invention spawned a huge business for casinos, even though forces of morality and the clergy frequently opposed their operation. By the 1920s laws restricting their sale and transportation and prohibiting them in private clubs were common. In the 1950s electronic components were added to allow many new payout schemes, such as 3- and 5-coin multipliers.

In Web development, a slot is a dynamic placeholder that either waits for content (passive) or calls out for it (active). Scenarios and renderers work in tandem with slots to deliver page content. For example, template v-slot:header> is the same as template #header>. Using the shorthand v-slot makes it easier to express what is required of a child component that is rendering based on a template. This is important because it prevents duplication of logic, such as conditional tags. For more information, see Rendering slots in the Render framework documentation.