escapement

 
Pronunciation: /ɪˈskeɪpm(ə)nt, ɛ-/

noun

  • 1a mechanism in a clock or watch that alternately checks and releases the train by a fixed amount and transmits a periodic impulse from the spring or weight to the balance wheel or pendulum: a lever escapement
  • 2a mechanism in a typewriter that shifts the carriage a small fixed amount to the left after a key is pressed and released.
  • 3the part of the mechanism in a piano that enables the hammer to fall back as soon as it has struck the string.

Origin:

late 18th century: from French échappement, from échapper 'to escape'