quack
UK: kwæk | US: kwæk
n. 1. The harsh sound made by a duck.
n. 2. A person who dishonestly claims to have medical knowledge or skills; a charlatan.
vi. 1. To make the sound of a duck.
vi. 2. To act as a medical fraud.
The word "quack" is onomatopoeic, directly mimicking the sound produced by ducks. Its secondary meaning, referring to a fraudulent medical practitioner, emerged in the 17th century, likely derived from the Dutch "kwakzalver" (literally "quack salver"), where "quack" implied boastful chatter and "salver" referred to someone applying ointments. The term humorously likened such charlatans to noisy, unsubstantial ducks.
The ducks began to quack loudly when they saw bread crumbs.
He was exposed as a quack after his fake remedies caused harm.
Children laughed at the duck’s persistent quacking.
Beware of quacks selling miracle cures online.
The pond echoed with the quacks of a dozen ducks.