cabyoudaoicibaDictYouDict[cab 词源字典]
cab: [19] Cab is short for cabriolet, a term, borrowed from French, for a light horse-drawn carriage. It comes, via the French verb cabrioler, from Italian capriolare ‘jump in the air’, a derivative of capriolo ‘roebuck’, from Latin capreolus, a diminutive form of caper ‘goat’ (source of English caper ‘leap’ and Capricorn). The reason for its application to the carriage was that the vehicle’s suspension was so springy that it appeared to jump up and down as it went along. From the same source comes the cabriole leg ‘curved furniture leg’ [18], from its resemblance to the front leg of a capering animal.
=> cabriole, cabriolet, caper, capricorn[cab etymology, cab origin, 英语词源]
cab (n.)youdaoicibaDictYouDict
1826, "light, horse-drawn carriage," shortening of cabriolet (1763), from French cabriolet (18c.), diminutive of cabrioler "leap, caper" (16c./17c.), from Italian capriolare "jump in the air," from capriola, properly "the leap of a kid," from Latin capreolus "wild goat, roebuck," from PIE *kap-ro- "he-goat, buck" (cognates: Old Irish gabor, Welsh gafr, Old English hæfr, Old Norse hafr "he-goat"). The carriages had springy suspensions.

Extended to hansoms and other types of carriages, then extended to similar-looking parts of locomotives (1851). Applied especially to public horse carriages, then to automobiles-for-hire (1899) when these began to replace them.