escapement

escape +‎ -ment. The watch component is so called because it allows a tooth to escape from a pallet at each vibration.

escapement (plural escapements)

1. The contrivance in a timepiece (winding wristwatch) which connects the train of wheel work with the pendulum or balance, giving to the latter the impulse by which it is kept in vibration.
   • 2010, Joseph Rabushka, Repair and Restore Your 400-Day Clock, →ISBN, page 53:

     For some reason, adjusting the 400-day clock escapement strikes fear into the hearts of many clock repairers.

2. A mechanism found in devices such as a typewriter or printer which controls lateral motion of the carriage.
3. An escape or means of escape.
4. The number of fish that escape commercial fishing operations and travel upstream to spawn.
   • 1999, E. Eric Knudsen & ‎Donald McDonald, Sustainable Fisheries Management: Pacific Salmon, →ISBN, page 237:

     Importantly, there are also extensive practical difficulties associated with gathering and interpreting accurate escapement and run-size information and applying it to population management.

   • 1999, Terrance J. Quinn & ‎Richard B. Deriso, Quantitative Fish Dynamics, →ISBN, page 432:

     They obtained migration information from a mark– recapture experiment, daily escapement information from aerial surveys, and daily catch information from fish tickets.

   • 2002, Dana Stabenow, A Fine and Bitter Snow, →ISBN, page 17-18:

     Who actually listens to us when we tell him we need to cut back on escapement in the Kanuyaq because too many salmon are getting past the dip netters and it's messing with the spawning beds?