Definitions
1.nounThe hole in a lock where the key is inserted and turns.
2.nounAny small opening resembling the hole for a key in shape or function.
3.nounA circle cut out of a garment as a decorative effect, typically at the front or back neckline of a dress.
4.nounA hole or excavation in beams intended to be joined together, to receive the key that fastens them.
5.nounA mortise for a key or cotter.
6.noun(lasers) A transient column of vapor or plasma formed when using high energy beams, such as lasers, for welding or cutting."keyhole plasma"
7.nounA 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.
8.nounThe free-throw lane together with the circle surrounding the free-throw line; key.
9.nounA gravitational keyhole.
10.verb(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.