[ kwak ]
/ kwæk /


the harsh, throaty cry of a duck or any similar sound.

verb (used without object)

to utter the cry of a duck or a sound resembling it.

Nearby words

  1. qu yuan,
  2. qu'appelle,
  3. qu.,
  4. qua,
  5. quaalude,
  6. quack grass,
  7. quacker,
  8. quackery,
  9. quacksalver,
  10. quaco

Origin of quack

1610–20; imitative; compare Dutch kwakken, German quacken


[ kwak ]
/ kwæk /


a fraudulent or ignorant pretender to medical skill.
a person who pretends, professionally or publicly, to skill, knowledge, or qualifications he or she does not possess; a charlatan.


verb (used with object)

to treat in the manner of a quack.
to advertise or sell with fraudulent claims.

Origin of quack

First recorded in 1620–30; short for quacksalver

Related formsquack·ish, adjectivequack·ish·ly, adverbquack·ish·ness, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for quack

British Dictionary definitions for quack


/ (kwæk) /

verb (intr)

(of a duck) to utter a harsh guttural sound
to make a noise like a duck


the harsh guttural sound made by a duck

Word Origin for quack

C17: of imitative origin; related to Dutch kwakken, German quacken


  1. an unqualified person who claims medical knowledge or other skills
  2. (as modifier)a quack doctor
British, Australian and NZ informal a doctor; physician or surgeon


(intr) to act in the manner of a quack
Derived Formsquackish, adjective

Word Origin for quack

C17: short for quacksalver

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for quack
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for quack


[ kwăk ]


An untrained person who pretends to be a physician and dispenses medical advice and treatment.
A charlatan.
Related formsquacker•y n.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.