keyway

1. A slot into which a precision attachment (a key) is fitted.

2. The whole deep way the key has to go, the hollow or cavity.

   Schlüsselbartaufnahme, Aussparung, Schlüsselsitz

3. A guide groove.

   Schlitz, Nut, Führungsrille

4. The recessed part of a keyed joint, in which the key resides.

   Near-synonyms: keyseat, groove

   Nut, Passfedernut

5. The groove within a modern lock that the key slides into; any lock's keyhole.

regular