A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately (via Dutch, Northern French, and Medieval Latin) from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece. In general usage today a "clock" refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on one's person are often distinguished from clocks.
The clock is one of the oldest human inventions, meeting the need to consistently measure intervals of time shorter than the natural units: the day; the lunar month; and the year. Devices operating on several different physical processes have been used over the millennia, culminating in the clocks of today.
The study of timekeeping is known as horology.
Famous quotes containing the word clock:
“The stars move still, time runs, the clock will strike,
The devil will come, and Faustus must be damned.
O Ill leap up to my God: who pulls me down?
See, see, where Christs blood streams in the firmament.
One drop would save my soul, half a drop, ah my Christ.”
—Christopher Marlowe (15641593)
“What brought them there so far from their home,
Cuchulain that fought night long with the foam,
What says the Clock in the Great Clock Tower?
Niamh that rode on it; lad and lass
That sat so still and played at the chess?
What but heroic wantonness?”
—William Butler Yeats (18651939)
“The clock of communism has stopped striking. But its concrete building has not yet come crashing down. For that reason, instead of freeing ourselves, we must try to save ourselves from being crushed by its rubble.”
—Alexander Solzhenitsyn (b. 1918)