• synonyms


  1. Machinery. a groove in a shaft, the hub of a wheel, etc., for receiving part of a key holding it to another part.
  2. a slot in a lock for receiving and guiding the key.
  3. (in poured-concrete construction) a longitudinal groove in a footing, or in a pour that has set, providing a key for newly poured concrete.
  4. a depression or slot carved into rock to provide a bond or anchorage for a structure, as a dam.
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Origin of keyway

First recorded in 1865–70; key1 + way1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for keyway

Historical Examples

  • The sides and bottom of the keyway should be surfaced true with the file.

    Modern Machine-Shop Practice, Volumes I and II

    Joshua Rose

  • This head is also driven by a key which engages a keyway in the boring-bar.

    Turning and Boring

    Franklin D. Jones

  • The flat key is used where it is necessary to secure the wheel more firmly without weakening the shaft by cutting a keyway in it.

  • The sleeve now stands still, the die cuts the thread and pulls the turret along by the friction of the pin in the keyway.

  • This causes the pin to catch in the front end of the keyway and the sleeve is again locked.

British Dictionary definitions for keyway


  1. 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
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012