quackyoudaoicibaDictYouDict[quack 词源字典]
quack: English has two words quack. The one denoting the call of a duck [17] originated of course as an imitation of the sound itself. Quack ‘person claiming to be a doctor’ [17] is short for an earlier quacksalver, which etymologically denoted ‘someone who prattles on or boasts about the efficacy of his remedies’. It was borrowed from early modern Dutch quacksalver, a compound formed from the now obsolete quacken ‘chatter, prattle’ and salf, the Dutch relative of English salve.
[quack etymology, quack origin, 英语词源]
quack (v.)youdaoicibaDictYouDict
"to make a duck sound," 1610s, earlier quake (1520s), variant of quelke (early 14c.), of echoic origin (compare Middle Dutch quacken, Old Church Slavonic kvakati, Latin coaxare "to croak," Greek koax "the croaking of frogs," Hittite akuwakuwash "frog"). Middle English on the quakke (14c.) meant "hoarse, croaking." Related: Quacked; quacking.
quack (n.1)youdaoicibaDictYouDict
"medical charlatan," 1630s, short for quacksalver (1570s), from obsolete Dutch quacksalver (modern kwakzalver), literally "hawker of salve," from Middle Dutch quacken "to brag, boast," literally "to croak" (see quack (v.)) + salf "salve," salven "to rub with ointment" (see salve (v.)). As an adjective from 1650s. The oldest attested form of the word in this sense in English is as a verb, "to play the quack" (1620s). The Dutch word also is the source of German Quacksalber, Danish kvaksalver, Swedish kvacksalvare.
quack (n.2)youdaoicibaDictYouDict
duck sound, 1839, from quack (v.).