1 of 5

verb (1)

quacked; quacking; quacks

intransitive verb

: to make the characteristic cry of a duck


2 of 5

noun (1)

: a noise made by quacking


3 of 5

verb (2)

quacked; quacking; quacks

intransitive verb

: to act like a quack


4 of 5

noun (2)

: charlatan sense 2
Religious quacks on radio and television thinking up new ways to take money from ignorant listeners and incidentally from legitimate churches.Andrew A. Rooney
: an ignorant, misinformed, or dishonest practitioner of medicine
No doubt these misunderstandings and dashed hopes have driven many cancer patients and their families into the arms of quacks.Haydn Bush
quackish adjective


5 of 5


: of, relating to, or used by quacks
quack cancer cures

Word History


Verb (1)

alteration of queck to quack, from Middle English queken, from queke, interjection, of imitative origin

Noun (2) and Verb (2)

short for quacksalver

First Known Use

Verb (1)

14th century, in the meaning defined above

Noun (1)

1798, in the meaning defined above

Verb (2)

1628, in the meaning defined above

Noun (2)

1638, in the meaning defined at sense 1


1653, in the meaning defined above

Time Traveler
The first known use of quack was in the 14th century

Dictionary Entries Near quack

Cite this Entry

“Quack.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quack. Accessed 4 Feb. 2023.

Kids Definition


1 of 4 noun
: the cry of a duck
also : a sound resembling this cry


2 of 4 verb
: to make a quack


3 of 4 noun
: a person who makes false claims to special knowledge or ability
especially : one who pretends to have medical skill


4 of 4 adjective
: of, relating to, or used by a person who is a quack
quack medicines

Medical Definition


1 of 2 noun
: a pretender to medical skill : an ignorant or dishonest practitioner
quackish adjective


2 of 2 adjective
: of, relating to, characteristic of, or being a quack
scores of quack remedies for arthritisJane E. Brody

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