Clock

A clock (from the Latin cloca, "bell") is an instrument for measuring time. The clock in its most common, modern form (in use since at least the 14th century) displays the time in hours, minutes, and often seconds during a 12- or 24-hour period.

Clocks used for technical purposes, of very high accuracy, are usually called chronometers. A common portable timekeeping instrument for personal use is the pocket or wrist watch.

True clocks also have an announcing or striking mechanism that sounds after each set interval of time, usually by ringing a bell (which, as previously indicated, originally gave the clock its name), chimes, or gong. A silent clock without a striking mechanism is traditionally known as a timepiece, a term sometimes used by horologists and other specialists to describe ordinary wrist watches and other timekeeping devices lacking a striking mechanism (see Baillie et al., p. 307; Palmer, p. 19; Zea & Cheney, p. 172).