late 14c., "a great outcry," also figurative, "loud or urgent demand," from Old French clamor "call, cry, appeal, outcry" (12c., Modern French clameur), from Latin clamor "a shout, a loud call" (either friendly or hostile), from clamare "to cry out" (from PIE root *kele- (2) "to shout").
"utter loudly, shout," also figurative, "make importunate demands or complaints," late 14c., from clamor (n.). Related: Clamored; clamoring.
noisy, vociferous," c. 1400, from Medieval Latin clamorosus, from Latin clamor "a shout" (see clamor (n.)). Related: Clamorously; clamorousness.
It forms all or part of: acclaim; acclamation; Aufklarung; calendar; chiaroscuro; claim; Claire; clairvoyance; clairvoyant; clamor; Clara; claret; clarify; clarinet; clarion; clarity; class; clear; cledonism; conciliate; conciliation; council; declaim; declare; disclaim; ecclesiastic; eclair; exclaim; glair; hale (v.); halyard; intercalate; haul; keelhaul; low (v.); nomenclature; paraclete; proclaim; reclaim; reconcile.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit usakala "cock," literally "dawn-calling;" Latin calare "to announce solemnly, call out," clamare "to cry out, shout, proclaim;" Middle Irish cailech "cock;" Greek kalein "to call," kelados "noise," kledon "report, fame;" Old High German halan "to call;" Old English hlowan "to low, make a noise like a cow;" Lithuanian kalba "language."
c. 1400, from Latin vociferationem (nominative vociferatio), "a loud calling, clamor, outcry," noun of action from past-participle stem of vociferari "to shout, yell, cry out" (see vociferous).
"unsubstantiated report, gossip, hearsay;" also "tidings, news, a current report with or without foundation," late 14c., from Old French rumor "commotion, widespread noise or report" (Modern French rumeur), from Latin rumorem (nominative rumor) "noise, clamor; common talk, hearsay, popular opinion," which is related to ravus "hoarse" (from PIE *reu- "to bellow").
Dutch rumoer, German Rumor are from French. The sense of "loud protest, clamor, outcry" also was borrowed in Middle English but is now archaic or poetic. Also compare rumorous "making a loud, confused sound" (1540s). Rumor-monger is by 1884 (earlier in that sense was rumorer, c. 1600). The figurative rumor mill is by 1887.
"pale grayish-green color," 1768, from French Céladon, name of a character in the once-popular romance of "l'Astrée" by Honoré d'Urfé (1610); an insipidly sentimental lover who wore bright green clothes, he is named in turn after Celadon (Greek Keladon), a character in Ovid's "Metamorphoses," whose name is said to mean "sounding with din or clamor." The mineral celadonite (1868) is so called for its color.