chronometer

As a noun chronometer

is a device for measuring time, such as a watch or clock.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between wristwatch and chronometer

is that wristwatch is a watch that is worn on a strap or band fastened around the wrist while chronometer is a device for measuring time, such as a watch or clock.

As nouns the difference between timer and chronometer

is that timer is someone or something which times while chronometer is a device for measuring time, such as a watch or clock.

Timepiece is a related term of chronometer.

As nouns the difference between timepiece and chronometer

is that timepiece is any device that measures or registers time; a clock or watch, especially one lacking a chime or other striking mechanism while chronometer is a device for measuring time, such as a watch or clock.

Horologe is a related term of chronometer.

As nouns the difference between horologe and chronometer

is that horologe is (obsolete) a clock or watch while chronometer is a device for measuring time, such as a watch or clock.

As a noun chronometer is

a device for measuring time, such as a watch or clock.