chronometer

/krəˈnɑmədər/

Other forms: chronometers

A chronometer is a type of device that measures time in a manner that is highly accurate — not your average, ordinary watch.

A chronometer is an exceptionally precise and stable timepiece that keeps accurate time even under harsh conditions. Marine chronometers, for example, must maintain accuracy despite the temperature fluctuations, humid conditions, and rocking motion that are common on ships at sea. The first practical marine chronometer was invented by John Harrison in the 18th century; it enabled navigators to accurately determine longitude, thus making maritime travel much safer. The word chronometer is built from Greek roots chronos, "time," and metron, "measure."

Definitions of chronometer

1. noun

   an accurate clock (especially used in navigation)
   type of:

   clock

   a timepiece that shows the time of day