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 (v.)
"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)
"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)
duck sound, 1839, from quack (v.).
中文解释
quack 发音“夸口”：外行爱夸口
实用例句
1. Why do intelligent people find quack remedies so appealing?
为什么聪明人会被江湖医术所吸引？
来自柯林斯例句
2. Suddenly he heard a quack.
他突然听见一声嘎嘎的叫声。
来自柯林斯例句
3. He describes himself as a doctor, but I feel he is a quack.
他自称是医生, 可是我感觉他是个江湖骗子.
来自《简明英汉词典》
4. That doctor's a quack!
那个医生是庸医!
来自《简明英汉词典》
5. For the rest it was just a noise, a quack - quack - quacking.