clock (n.1)

"machine to measure and indicate time mechanically" (since late 1940s also electronically), late 14c., clokke, originally "clock with bells," probably from Middle Dutch clocke (Dutch klok) "a clock," from Old North French cloque (Old French cloke, Modern French cloche "a bell"), from Medieval Latin clocca "bell," which probably is from Celtic (compare Old Irish clocc, Welsh cloch, Manx clagg "a bell") and spread by Irish missionaries (unless the Celtic words are from Latin). Ultimately of imitative origin.

Wherever it actually arose, it was prob. echoic, imitating the rattling made by the early handbells of sheet-iron and quadrilateral shape, rather than the ringing of the cast circular bells of later date. [OED]

Replaced Old English dægmæl, from dæg "day" + mæl "measure, mark" (see meal (n.1)). The Latin word was horologium (source of French horologe, Spanish reloj, Italian oriolo, orologio); the Greeks used a water-clock (klepsydra, literally "water thief;" see clepsydra).

The image of put (or set) the clock back "return to an earlier state or system" is from 1862. Round-the-clock (adj.) is from 1943, originally in reference to air raids. To have a face that would stop a clock "be very ugly" is from 1886. (Variations from c. 1890 include break a mirror, kill chickens.)

I remember I remember
That boarding house forlorn,
The little window where the smell
Of hash came in the morn.
I mind the broken looking-glass,
The mattress like a rock,
The servant-girl from County Clare,
Whose face would stop a clock.
[... etc.; The Insurance Journal, January 1886]
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clock (v.)

"to time by the clock," 1883, from clock (n.1). The slang sense of "hit, sock" is 1941, originally Australian, probably from earlier slang clock (n.) "face" (1923). To clock in "register one's arrival by means of a mechanical device with a clock" is from 1914. Related: Clocked; clocking.

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clock (n.2)

"ornament pattern on a stocking," 1520s, probably identical with clock (n.1) in its older sense and meaning "bell-shaped ornament," though clock seems never to have been used for "bell" in English. Related: Clocked; clock-stocking.

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clock-maker (n.)

"one who makes clocks," mid-15c., from clock (n.1) + maker.

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clock-watcher (n.)
"employee habitually prompt in leaving," 1887, from clock (n.1) + agent noun from watch (v.). Related: Clock-watching. Compare earlier tell-clock "idler" (c. 1600).
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clock-radio (n.)

"combined bedside radio and alarm clock which can be set to turn on the radio instead of sounding the alarm," 1946, from clock (n.1) + radio (n.).

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clock-tower (n.)

"tower containing a clock," usually a large one with dials exposed on all four sides, 1757, from clock (n.1) + tower (n.). Older words for this were clocher (14c., from Old French), belfry.

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clockwise (adv.)

also clock-wise, "in the direction of the rotation of the hands of a clock," 1879, from clock (n.1) + wise (n.).

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clockwork (n.)

also clock-work, 1660s, "machinery and movements of a clock," from clock (n.1) + work (n.). Figurative sense of "any regulated system of unvarying regularity" is recorded earlier (1620s); also as an adjective in this sense (1760s).

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cloche (n.)
type of bell-jar, 1882, from French cloche "bell, bell glass" (12c.), from Late Latin clocca "bell" (see clock (n.1)). As a type of women's hat, recorded from 1907, so called from its shape.
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