pawl

 
Pronunciation: /pɔːl/

noun

  • a pivoted curved bar or lever whose free end engages with the teeth of a cogwheel or ratchet so that the wheel or ratchet can only turn or move one way.
  • each of a set of short bars that engage with the whelps and prevent a capstan, windlass, or winch from recoiling.

Origin:

early 17th century: perhaps from Low German and Dutch pal (related to pal 'fixed')