Quack Definition

kwăk

quacking, quacks

noun

The sound made by a duck, or any sound like it.

Webster's New World

An untrained person who practices medicine fraudulently.

Webster's New World

Any person who pretends to have knowledge or skill in a particular field; charlatan.

Webster's New World

A charlatan; a mountebank.

American Heritage

Carlyle.

Wiktionary

Synonyms:

verb

To utter the characteristic sound or cry of a duck, or a sound like it.

Webster's New World

To act as a medical quack or a charlatan.

American Heritage Medicine

To engage in quackery.

Webster's New World

To make a noise like a duck.

The more breadcrumbs I threw on the ground, the more they quacked.

Do you hear the ducks quack?

Wiktionary

adjective

Relating to or characteristic of a quack.

A quack cure.

American Heritage Medicine

Characterized by pretentious claims with little or no foundation.

Webster's New World

Dishonestly claiming to effect a cure.

Webster's New World

Falsely presented as having medicinal powers.

Don't get your hopes up; that's quack medicine!

Wiktionary

Antonyms:

Other Word Forms of Quack

Singular:

quack

Plural:

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 *kwakanÄ…, *kwakōnÄ… (“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").

From Wiktionary
c 1630, shortening of quacksalver, from Middle Dutch kwaksalver (“hawker of salve") (Dutch kwakzalver), from quacken (“to brag, boast; to croak")

From Wiktionary
Middle English quek of imitative origin

From American Heritage Dictionary of the English Language, 5th Edition
Short for quacksalver

From American Heritage Dictionary of the English Language, 5th Edition