chronometer

noun

Etymology: From chrono- + -meter, possibly after the model of earlier French chronomètre (“metronome”), ultimately from Ancient Greek χρόνος (khrónos, “time”) + μέτρον (métron, “meter, measuring device”).

1. A device for measuring time, particularly a precision mechanism for measuring time of day.

   “A wristwatch costs $20; a chronometer costs $20,000.”

   “The balances of all moveable time-keepers, the chronometer excepted, are prevented from vibrating beyond the proper arc by what is called bankings. The inferior escapements are very easily banked; a pin fixed in the balance, coming in contact with one or two studs, is sufficient for that purpose. […]”