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 source of poetry that
seeing the clock stopped, says,
The clock has stopped
that ticked yesterday so well?”
—William Carlos Williams (18831963)
“We are hardly ever grateful for a fine clock or watch when it goes right, and we pay attention to it only when it falters, for then we are caught by surprise. It ought to be the other way about.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (16941773)