keyway

/ˈkiːweɪ/
noun
  1. A slot or groove cut into a shaft or a hub to hold a key that prevents rotation between the two parts.
    • The mechanic cut a keyway into the shaft to secure the gear.
    • A keyway ensures that the pulley rotates with the axle.
    • The machine part had a keyway machined to exact specifications.
Synonyms
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