Slot is a narrow aperture or groove. In aviation, it can refer to a gap between the wing and an auxiliary airfoil, or to a slot in the fuselage. It can also refer to a mechanism that provides clearance for the journal of a wheel or axle shaft.

In the NFL, a slot receiver is a player who lines up on shorter routes on the route tree—such as slants and quick outs—but can stretch the defense vertically with their speed. Slot receivers are a growing trend in the game because of their effectiveness in both the run and pass games.

The slot> element can contain one of several global attributes:

A signal connected to slots is emitted when the state of the object that owns the slot changes. Like signals, slots are normal member functions. However, unlike signals, they do not know whether they have any receivers, and do not need to be declared anywhere in the code. This is an important feature, as it enables truly independent components to be created with Qt.

Psychologists have found that players of video slot machines reach debilitating levels of gambling involvement three times faster than those who play other casino games. The fast turnover rate and high reward-to-risk ratio of these machines are the primary reasons for this finding. In addition, the presence of near-miss events—in which feedback for a loss approximates a win—may reinforce continued play. These findings have led many to speculate that slot machines are addictive.