from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The characteristic sound uttered by a duck.
  • intransitive verb To utter the characteristic sound of a duck.
  • noun An untrained person who pretends to be a physician and dispenses medical advice and treatment.
  • noun A charlatan; a mountebank.
  • adjective Relating to or characteristic of a quack.
  • intransitive verb To act as a medical quack or a charlatan.

from The Century Dictionary.

  • To utter a harsh, flat, croaking sound or cry, as a goose or duck; croak; now, usually, to cry as a duck.
  • To make an outcry: said of persons.
  • noun A harsh, croaking sound.
  • noun The cry of a duck; a quacking.
  • noun See couac.
  • To talk noisily and ostentatiously; make vain and loud pretensions.
  • To play the quack; practise arts of quackery, as a pretender to medical skill.
  • To treat in the manner of a quack; play the quack with.
  • To tamper with dishonestly; use fraudulently.
  • noun An impudent and fraudulent pretender to medical skill; a mountebank; a knavish practitioner of medicine.
  • noun Hence One who pretends to skill or knowledge of any kind which he does not possess; an ignorant and impudent pretender; a charlatan.
  • noun Synonyms Quack, Empiric, Mountebank, Charlatan. A quack is, by derivation, one who talks much without wisdom, and, specifically, talks of his own power to heal; hence, any ignorant pretender to medical knowledge or skill. Empiric is a more elevated term for one who goes by mere experience in the trial of remedies, and is without knowledge of the medical sciences or of the clinical observations and opinions of others; hence, an incompetent, self-confident practitioner. A mountebank is generally a quack, but may be a pretender in any line. Charlatan (literally ‘chatterer’) is primarily applied, not to a person belonging to any particular profession or occupation, but to a pretentious cheat of any sort.
  • Pertaining to or characterized by quackery of any kind; specifically, falsely pretending to cure disease, or ignorantly or fraudulently set forth as remedies: as, a quack doctor; quack medicines.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Pertaining to or characterized by, boasting and pretension; used by quacks; pretending to cure diseases
  • intransitive verb To utter a sound like the cry of a duck.
  • intransitive verb To make vain and loud pretensions; to boast.
  • intransitive verb To act the part of a quack, or pretender.
  • noun The cry of the duck, or a sound in imitation of it; a hoarse, quacking noise.
  • noun A boastful pretender to medical skill; an empiric; an ignorant practitioner.
  • noun Hence, one who boastfully pretends to skill or knowledge of any kind not possessed; a charlatan.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun The sound made by a duck.
  • verb To make a noise like a duck.
  • noun A fraudulent healer or incompetent doctor of medicine, an impostor who claims to have qualifications to practice medicine.
  • noun A charlatan.
  • noun slang A doctor.
  • verb To practice, commit quackery.
  • adjective falsely presented as having medicinal powers.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun an untrained person who pretends to be a physician and who dispenses medical advice
  • verb act as a medical quack or a charlatan
  • verb utter quacking noises
  • adjective medically unqualified
  • noun the harsh sound of a duck


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English quek, of imitative origin.]

from The American Heritage® Dictionary of the English Language, 4th Edition

[Short for quacksalver.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English *quacken, queken ("to croak like a frog; make a noise like a duck, goose, or quail"), from quack, qwacke, quek, queke ("quack", interjection and noun), also kek, keke, whec-, partly of imitative origin and partly from Middle Dutch quacken ("to croak, quack"), from Old Dutch *kwaken ("to croak, quack"), from Proto-Germanic *kwakanan, *kwakōnan (“to croak”), of imitative origin. Cognate with Saterland Frisian kwoakje, Middle Low German quaken ("to quack, croak"), German quaken ("to quack, croak"), Danish kvække ("to croak"), Swedish kväka ("to croak, quackle"), Norwegian kvekke ("to croak"), Icelandic kvaka ("to twitter, chirp").


Help support Wordnik (and make this page ad-free) by adopting the word quack.



Log in or sign up to get involved in the conversation. It's quick and easy.

  • A duck's quack doesn't echo, and no one knows why.

    May 7, 2008

  • Does a quack's quack echo? And if it does, should it be listened to?

    May 7, 2008

  • What is the sound of two ducks quacking?

    May 7, 2008

  • I'm going to kidnap a duck and take it to my echo chamber to research this one properly.

    May 7, 2008

  • If a duck quacks in the forest and the pope isn't there to listen . . .

    May 7, 2008

  • What is the sound of bilby kidnapping a duck and taking it to his echo chamber?

    May 7, 2008

  • It's bong.

    Look at WeirdNet's fifth definition of quack. Five is a nice number. Nice is a city in France. In the French revolution heads were chopped off. Offal is disgusting. Other gusts are windy and I have a list of those. I would like to make a list of phrasal verbs but I'm too lazy. But PVs usually have two components. And the second definition of bong is ...


    May 7, 2008

  • *causes an audible event to occur suddenly*

    May 7, 2008

  • okaaaay... *backs away slowly*

    May 7, 2008

  • *passes nose-peg*

    May 7, 2008

  • Oh, please. It was a laugh. I don't laugh that awfully.

    May 7, 2008

  • A laugh? I thought you were going "BONNNNNNNNNNNNNG".

    May 7, 2008

  • Well, it's clear we don't have sound on this page. ;->

    May 7, 2008

  • Nigerian English - To tackle or trip.

    Example: Man as I dey play football Chigozie just quack me for no reason.

    June 21, 2009