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:
“I open with a clock striking, to beget an awful attention in the audienceit also marks the time, which is four oclock in the morning, and saves a description of the rising sun, and a great deal about gilding the eastern hemisphere.”
—Richard Brinsley Sheridan (17511816)
“Stands the Church clock at ten to three?
And is there honey still for tea?”
—Rupert Brooke (18871915)
“Pop Wyman ruled here with a firm but gentle hand; no drunken man was ever served at the bar; no married man was allowed to play at the tables; across the face of the large clock was written Please Dont Swear, and over the orchestra appeared the gentle admonition, Dont Shoot the PianistHes Doing His Damndest.”
—Administration in the State of Colo, U.S. public relief program. Colorado: A Guide to the Highest State (The WPA Guide to Colorado)