clapboard (n.) Look up clapboard at Dictionary.com
1520s, partial translation of Middle Dutch klapholt (borrowed into English late 14c. as clapholt), from klappen "to fit" + Low German holt "wood, board" (see holt). Compare German Klappholz. Originally small boards of split oak, imported from northern Germany and cut by coopers to make barrel staves; the meaning "long, thin board used for roofing or to cover the exterior of wooden buildings" is from 1640s, American English.
clapper (n.) Look up clapper at Dictionary.com
late 13c., agent noun from clap (v.). Meaning "tongue of a bell" is from late 14c. Old English had clipur. Meaning "hinged board snapped in front of a camera at the start of filming to synchronize picture and sound" is from 1940.
clapperclaw (v.) Look up clapperclaw at Dictionary.com
"to fight at arm's length with the hands and nails," 1590s, from clap (v.) + claw (v.). Related: Clapperclawed; clapperclawing.
claptrap (n.) Look up claptrap at Dictionary.com
c. 1730, "trick to 'catch' applause," a stage term; from clap (v.) + trap (n.). Extended sense of "cheap, showy language" is from 1819; hence "nonsense, rubbish."
claque (n.) Look up claque at Dictionary.com
1860, from French claque "band of claqueurs," agent noun from claquer "to clap" (16c.), echoic (compare clap (v.)). Modern sense of "band of political followers" is transferred from that of "organized applause at theater." Claqueur "audience memeber who gives pre-arranged responses in a theater performance" is in English from 1837.
This method of aiding the success of public performances is very ancient; but it first became a permanent system, openly organized and controlled by the claquers themselves, in Paris at the beginning of the nineteenth century. [Century Dictionary]
Clara Look up Clara at Dictionary.com
fem. personal name, from Latin Clara, from fem. of clarus "bright, shining, clear" (see clear (adj.) and compare Claire). Derivatives include Clarisse, Clarice, Clarabel, Claribel. The native form Clare was common in medieval England, perhaps owing to the popularity of St. Clare of Assisi.
Clarence Look up Clarence at Dictionary.com
surname, from Medieval Latin Clarencia, name of dukedom created 1362 for Lionel, third son of Edward III, so called from town of Clare, Suffolk, whose heiress Lionel married. Used as a masc. proper name from late 19c. As a type of four-wheeled closed carriage, named for the Duke of Clarence, later William IV.
clarendon (n.) Look up clarendon at Dictionary.com
a thickened Roman type face, 1845, evidently named for the Clarendon press at Oxford University, which was set up 1713 in the Clarendon Building, named for university Chancellor Edward Hyde, 1st Earl of Clarendon.
claret (n.) Look up claret at Dictionary.com
mid-15c., "light-colored wine," from Old French (vin) claret "clear (wine), light-colored red wine" (also "sweetened wine," a sense in English from late 14c.), from Latin clarus "clear" (see clear (adj.)). Narrowed English meaning "red wine of Bordeaux" (excluding burgundy) first attested 1700. Used in pugilistic slang for "blood" from c. 1600.
clarification (n.) Look up clarification at Dictionary.com
1610s, "act of clearing or refining" (especially of liquid substances), from French clarification, from Late Latin clarificationem (nominative clarificatio), noun of action from past participle stem of clarificare (see clarify). The meaning "statement revising or expanding an earlier statement but stopping short of a correction" is attested by 1969, originally in newspapers.
clarify (v.) Look up clarify at Dictionary.com
early 14c., "make illustrious, make known," from Old French clarifiier "clarify, make clear, explain" (12c.), from Late Latin clarificare "to make clear," also "to glorify," from Latin clarificus "brilliant," from clarus "clear, distinct" (see clear (adj.)) + combining form of facere "to make, to do" (from PIE root *dhe- "to set, put").

Meaning "make clear, purify" is from early 15c. in English; intransitive sense of "grow or become clear" is from 1590s. Figurative sense of "to free from obscurity" is from 1823. Related: Clarified; clarifying.
clarinet (n.) Look up clarinet at Dictionary.com
1768, from French clarinette (18c.), diminutive of clarine "little bell" (16c.), noun use of fem. of adjective clarin (which also was used as a noun, "trumpet, clarion"), from clair, cler, from Latin clarus (see clear (adj.)). Alternative form clarionet is attested from 1784.

The instrument, a modification of the medieval shawm, said to have been invented c. 1700 by J.C. Denner of Nuremberg, Germany. A recognized orchestral instrument from c. 1775. Ease of playing increased greatly with a design improvement from 1843 based on Boehm's flute.
After the hautboy came the clarinet. This instrument astonished every beholder, not so much, perhaps, on account of its sound, as its machinery. One that could manage the keys of a clarinet, forty five years ago, so as to play a tune, was one of the wonders of the age. Children of all ages would crowd around the performer, and wonder and admire when the keys were moved. [Nathaniel D. Gould, "Church Music in America," Boston, 1853]
German Clarinet, Swedish klarinett, Italian clarinetto, etc. all are from French. Related: Clarinettist.
clarion (n.) Look up clarion at Dictionary.com
"small, high-pitched type of trumpet," early 14c., from Old French clarion "(high-pitched) trumpet, bugle" and directly from Medieval Latin clarionem (nominative clario) "a trumpet," from Latin clarus "clear" (see clear (adj.)). Clarion call is attested from 1838.
Clarisse Look up Clarisse at Dictionary.com
fem. proper name, often a diminutive of Clara and its relatives. Also, "a nun of the order of St. Clare" (1790s); the Franciscan order also known as the Poor Clares (c. 1600).
clarity (n.) Look up clarity at Dictionary.com
c. 1300, clarte "brightness," from Old French clarté "clarity, brightness," from Latin claritas "brightness, splendor," also, of sounds, "clearness;" figuratively "celebrity, renown, fame," from clarare "make clear," from clarus "clear" (see clear (adj.)). Modern form is early 15c., perhaps a reborrowing from Latin. Meaning "clearness" is from 1610s.
Clark Look up Clark at Dictionary.com
surname, from common Middle English alternative spelling of clerk (n.). In many early cases it is used of men who had taken minor orders.
clash (v.) Look up clash at Dictionary.com
c. 1500, "to make a loud, sharp sound," of imitative origin, or a blend of clap and crash. Compare Dutch kletsen "splash, clash," German klatschen, Danish klaske "clash, knock about." Figurative sense, in reference to non-physical strife or battle, is first attested 1620s. Of things, "to come into collision," from 1650s; of colors, "to go badly together," first recorded 1894. Related: Clashed; clashing.
clash (n.) Look up clash at Dictionary.com
1510s, "sharp, loud noise of collision," from clash (v.). Especially of the noise of conflicting metal weapons. Meaning "hostile encounter" is from 1640s; meaning "conflict of opinions, etc." is from 1781.
clasp (v.) Look up clasp at Dictionary.com
late 14c., from clasp (n.). Related: Clasped; clasping.
clasp (n.) Look up clasp at Dictionary.com
c. 1300, claspe, "metal catch or hook used to hold things together," perhaps a metathesis of clapse, and thus from or related to Old English clyppan "clasp" (see clip (v.2)).
clasp-hook (n.) Look up clasp-hook at Dictionary.com
1841, from clasp (n.) + hook (n.).
class (v.) Look up class at Dictionary.com
1705, "to divide into classes," from class (n.) or French classer. Sense of "to place into a class" is from 1776. Related: Classed; classing.
class (n.) Look up class at Dictionary.com
c. 1600, "group of students," from French classe (14c.), from Latin classis "a class, a division; army, fleet," especially "any one of the six orders into which Servius Tullius divided the Roman people for the purpose of taxation;" traditionally originally "the people of Rome under arms" (a sense attested in English from 1650s), and thus akin to calare "to call (to arms)," from PIE root *kele- (2) "to shout." In early use in English also in Latin form classis.

School and university sense of "course, lecture" (1650s) is from the notion of a form or lecture reserved to scholars who had attained a certain level. Natural history sense is from 1753. Meaning "a division of society according to status" (upper, lower, etc.) is from 1772. Meaning "high quality" is from 1847. Class-consciousness (1903) is from German klassenbewusst.
classic (adj.) Look up classic at Dictionary.com
1610s, "of the highest class; approved as a model," from French classique (17c.), from Latin classicus "relating to the (highest) classes of the Roman people," hence, "superior," from classis (see class). Originally in English, "of the first class;" meaning "belonging to standard authors of Greek and Roman antiquity" is attested from 1620s.
classic (n.) Look up classic at Dictionary.com
"a Greek or Roman writer or work," 1711, from classic (adj.). So, by mid-19c., any work in any context held to have a similar quality or relationship. In classical Latin noun use of classicus meant "a Marine" (miles classicus) from the "military division" sense of classis.
classical (adj.) Look up classical at Dictionary.com
1590s, "of the highest rank" (originally in literature), from classic + -al (1). Classical music (1836) was defined originally against romantic music.
[I]n general, as now used, the term classical includes the composers active in instrumental music from somewhere about 1700 to say 1830. Hence the list includes among the great names those of Bach, his sons, Haydn, Mozart, Beethoven, Clementi, Dussek, Pleyel, Cramer, etc. The next step beyond the term classical is "modern romantic," the composers of which school may be taken to include all the writers for pianoforte from about 1829 (when Mendelssohn published the first "Songs without Words") down to the present. The term romantic in this sense means strongly marked, extraordinary, intending to tell stories and the like. ["Music, Its Ideals and Methods," W.S.B. Mathews, 1897]
But already by 1880s it was acknowledged the term had a double sense: Music that had withstood the test of time, as well as music of a style contrasted to "romantic." Later (early 20c.) it was contrasted to jazz (in this sense more often with reference to the orchestras than to the music itself). Still later in contrast to popular music generally (mid-20c.). Classical history is the history of ancient Greece and Rome; ancient history is the history of mankind from the earliest reliable records to the fall of Rome (476 C.E.).
classicism (n.) Look up classicism at Dictionary.com
"classical style in art or literature," 1830, from classic + -ism. Related: Classicist.
classics (n.) Look up classics at Dictionary.com
"Greek and Roman writers and works," 1711, from classic (adj.).
classifiable (adj.) Look up classifiable at Dictionary.com
1820, from classify + -able.
classification (n.) Look up classification at Dictionary.com
1772, "action of classifying," noun of action from Latin stem of classify, or from French classification. Meaning "result of classifying" is from 1789.
classificatory (adj.) Look up classificatory at Dictionary.com
1825, from Latin stem of classify + -ory.
classified (adj.) Look up classified at Dictionary.com
"arranged in classes," 1828, past participle adjective from classify. Meaning "secret" (of government information) is from 1941, American English. Classifieds (n.) "newspaper advertisements arranged by classes," 1913, is short for classified advertisements
classify (v.) Look up classify at Dictionary.com
1782, from French classifier, from classe (see class (n.)) + -fier (see -fy). Related: Classified; classifying.
classism (n.) Look up classism at Dictionary.com
"distinction of class," 1842, from class (n.) + -ism.
classless (adj.) Look up classless at Dictionary.com
1874 in the social sense (1863 in reference to class generally), from class (n.) in the "social order" sense + -less. As "lacking the sophistication of high class," by 1979. Related: Classlessly; classlessness.
classmate (n.) Look up classmate at Dictionary.com
"one of the same class at school or college," 1713, from class (n.) + mate (n.).
classroom (n.) Look up classroom at Dictionary.com
also class-room, 1811, from class (n.) + room (n.).
classy (adj.) Look up classy at Dictionary.com
"pertaining to or characteristic of a (high) class," 1891, from class (n.) + -y (2). Related: Classily; classiness.
clastic (adj.) Look up clastic at Dictionary.com
"consisting of broken pieces," 1875, in geology, from Latinized form of Greek klastos "broken in pieces," from klan, klaein "to break," from PIE *kla-, variant of root *kel- (1) "to strike" (see holt).
clatter (v.) Look up clatter at Dictionary.com
late Old English clatrung "clattering, noise," verbal noun implying an Old English *clatrian, of imitative origin. Compare Middle Dutch klateren, East Frisian klatern, dialectal German klattern; perhaps from PIE root *gal- "to call, shout." The noun is attested from mid-14c.
Claude Look up Claude at Dictionary.com
masc. proper name, from French form of Claudius.
Claudia Look up Claudia at Dictionary.com
fem. proper name, from Latin Claudius (m.).
claudication (n.) Look up claudication at Dictionary.com
1550s, from Middle French claudication (13c.) or directly from Latin claudicationem (nominative claudicatio) "a limping," noun of action from past participle stem of claudicare "to limp, be lame," from claudus "limping, halting, lame." Related: Claudicant (adj.); claudicate.
Claudius Look up Claudius at Dictionary.com
masc. proper name, from the name of two Roman gentes, perhaps related to claudus "lame," which is of unknown origin. Related: Claudian.
clausal (adj.) Look up clausal at Dictionary.com
1870, from clause + -al (1).
clause (n.) Look up clause at Dictionary.com
c. 1200, "a sentence, a brief statement, a short passage," from Old French clause "stipulation" (in a legal document), 12c., from Medieval Latin clausa "conclusion," used in the sense of classical Latin clausula "the end, a closing, termination," also "end of a sentence or a legal argument," from clausa, fem. noun from past participle of claudere "to close, to shut, to conclude" (see close (v.)). Grammatical sense is from c. 1300. Legal meaning "distinct condition, stipulation, or proviso" is recorded from late 14c. in English. The sense of "ending" seems to have fallen from the word between Latin and French.
claustral (adj.) Look up claustral at Dictionary.com
"resembling a cloister," early 15c., from Middle French claustral (15c.) and directly from Medieval Latin claustralis "pertaining to a claustrum" (see cloister).
claustration (n.) Look up claustration at Dictionary.com
1863, "act of shutting up in a cloister," as if from a noun of action formed in Latin from Latin claustrare, from claustrum (see cloister).
claustrophilia (n.) Look up claustrophilia at Dictionary.com
"morbid desire to be shut up in a confined space," 1884, from claustro-, abstracted from claustrophobia, + -philia.
claustrophobia (n.) Look up claustrophobia at Dictionary.com
"morbid fear of being shut up in a confined space," coined 1879 (in article by Italian-born, French-naturalized Swiss-English physician Dr. Benjamin Ball (1834-1892)) from Latin claustrum "a bolt, a means of closing; a place shut in, confined place, frontier fortress" (in Medieval Latin "cloister"), past participle of claudere "to close" (see close (v.)) + -phobia "fear."