- The hole in a lock where the key is inserted and turns.
- Any small opening resembling the hole for a key in shape or function.
- A circle cut out of a garment as a decorative effect, typically at the front or back neckline of a dress.
- (carpentry) A hole or excavation in beams intended to be joined together, to receive the key that fastens them.
- (engineering) A mortise for a key or cotter.
- (lasers) A transient column of vapor or plasma formed when using high energy beams, such as lasers, for welding or cutting.
- laser keyhole welding
- keyhole plasma
- (metallurgy) A welding method in which a hole forms in the surface immediately ahead of the puddle in the direction of welding. The hole is filled as the weld progresses.
- (basketball) The free-throw lane together with the circle surrounding the free-throw line; key.
- (ordnance) To strike a target after wobbling in flight so that the long axis of the bullet does not follow the line of flight; typically due to insufficient spin resulting from the rifling in the barrel.
a hole to lock/unlock with a key