cloak-room (n.)youdaoicibaDictYouDict[cloak-room 词源字典]
also cloakroom, 1852, from cloak (n.) + room (n.).[cloak-room etymology, cloak-room origin, 英语词源]
clobber (v.)youdaoicibaDictYouDict
1941, British air force slang, probably related to bombing; possibly echoic. Related: Clobbered; clobbering. In late 19c. British slang the word principally had to do with clothing, as in clobber (n.) "clothes," (v.) "to dress smartly;" clobber up "to patch old clothes for reuse."
cloche (n.)youdaoicibaDictYouDict
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.
clock (n.1)youdaoicibaDictYouDict
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), from Medieval Latin (7c.) clocca "bell," probably 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.

Replaced Old English dægmæl, from dæg "day" + mæl "measure, mark" (see meal (n.1)). The Latin word was horologium; the Greeks used a water-clock (klepsydra, literally "water thief"). 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.)
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," Jan. 1886]
clock (v.)youdaoicibaDictYouDict
"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). Related: Clocked; clocking.
clock (n.2)youdaoicibaDictYouDict
"ornament pattern on a stocking," 1520s, probably identical with clock (n.1) in its older sense and meaning "bell-shaped ornament."
clock-radio (n.)youdaoicibaDictYouDict
1946, from clock (n.1) + radio (n.).
clock-watcher (n.)youdaoicibaDictYouDict
"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).
clockwise (adv.)youdaoicibaDictYouDict
also clock-wise, "in the direction of the hands of a clock," 1879, from clock (n.1) + wise (n.).
clockwork (n.)youdaoicibaDictYouDict
also clock-work, 1660s, "mechanism of a clock," from clock (n.1) + work (n.). Figurative sense of "anything of unvarying regularity" is recorded earlier (1620s).
clod (n.)youdaoicibaDictYouDict
"lump of earth or clay," Old English clod- (in clodhamer "the fieldfare," a kind of thrush, literally "field-goer"), from Proto-Germanic *kludda-, from PIE *gleu- (see clay).

Synonymous with collateral clot until meaning differentiated 18c. Meaning "person" ("mere lump of earth") is from 1590s; that of "blockhead" is from c. 1600 (compare clodpate, clodpoll, etc.). It also was a verb in Middle English, meaning both "to coagulate, form into clods" and "to break up clods after plowing."
cloddish (adj.)youdaoicibaDictYouDict
1844, from clod (n.) + -ish. Related: Clodishly; clodishness.
clodhopper (n.)youdaoicibaDictYouDict
1690s, slang, "one who works on plowed land, a rustic," from clod (n.) + agent noun from hop (v.). Compare in a similar sense clod-breaker, clod-crusher; in this word perhaps a play on grasshopper. Sense extended by 1836 to the shoes worn by such workers.
clog (n.)youdaoicibaDictYouDict
early 14c., clogge "a lump of wood," origin unknown. Also used in Middle English of large pieces of jewelry and large testicles. Compare Norwegian klugu "knotty log of wood." Meaning "anything that impedes action" is from 1520s. The sense of "wooden-soled shoe" is first recorded late 14c.; they were used as overshoes until the introduction of rubbers c. 1840. Originally all wood (hence the name), later wooden soles with leather uppers for the front of the foot only. Later revived in fashion (c. 1970), primarily for women. Clog-dancing is attested from 1863.
clog (v.)youdaoicibaDictYouDict
late 14c., "hinder," originally by fastening a block of wood to something, from clog (n.). Meaning "choke up with extraneous matter" is 17c. Related: Clogged; clogging.
cloison (n.)youdaoicibaDictYouDict
"a partition, a dividing band," 1690s, from French cloison, from Vulgar Latin *clausionem (nominative *clausio), noun of action from past participle stem of Latin claudere "to close, shut" (see clause). Related: Cloisonnage.
cloisonne (adj.)youdaoicibaDictYouDict
"divided into compartments," 1863, from French cloisonné, from cloison "a partition" (12c., in Old French, "enclosure"), from Provençal clausio, from Vulgar Latin *clausio, noun of action from past participle stem of claudere "to close, shut" (see clause).
cloister (n.)youdaoicibaDictYouDict
early 13c., from Old French cloistre "monastery, convent; enclosure" (12c., Modern French cloître), from Medieval Latin claustrum "portion of monastery closed off to laity," from Latin claustrum (usually in plural, claustra) "place shut in, enclosure; bar, bolt, means of shutting in," from past participle stem of claudere (see close (v.)).

"The original purpose of cloisters was to afford a place in which the monks could take exercise and recreation" [Century Dictionary]. Spelling in French influenced by cloison "partition." Old English had clustor, clauster in the sense "prison, lock, barrier," directly from Latin, and compare, from the same source, Dutch klooster, German Kloster, Polish klasztor.
cloister (v.)youdaoicibaDictYouDict
c. 1400 (implied in cloistered), from cloister (n.). Figurative use from c. 1600. Related: Cloistered; cloistering.
cloistral (adj.)youdaoicibaDictYouDict
c. 1600, from cloister + -al (1).