aplombyoudaoicibaDictYouDict[aplomb 词源字典]
aplomb: [18] Originally, aplomb meant literally ‘quality of being perpendicular’. It was borrowed from French, where it was a lexicalization of the phrase à plomb ‘according to the plumb line’ (plomb came from Latin plumbum ‘lead’, also the ultimate source of English plumb, plumber, plumbago, and plummet). The notion of ‘uprightness’ gave rise in the 19th century to the metaphorical sense ‘composure’.
=> plumb, plumber, plummet[aplomb etymology, aplomb origin, 英语词源]
aplomb (n.)youdaoicibaDictYouDict
"assurance, confidence," 1828, from French aplomb (16c.), literally "perpendicularity," from phrase à plomb "poised upright, balanced," literally "on the plumb line," from Latin plumbum "(the metal) lead" (see plumb (n.)), of which the weight at the end of the line was made.