noun
- Machinery. a groove in a shaft, the hub of a wheel, etc., for receiving part of a key holding it to another part.
- a slot in a lock for receiving and guiding the key.
- (in poured-concrete construction) a longitudinal groove in a footing, or in a pour that has set, providing a key for newly poured concrete.
- a depression or slot carved into rock to provide a bond or anchorage for a structure, as a dam.
noun
- a longitudinal slot cut into a component to accept a key that engages with a similar slot on a mating component to prevent relative motion of the two components