QUACK

quack

(adjective) medically unqualified; “a quack doctor”

quack

(noun) the harsh sound of a duck

quack

(noun) an untrained person who pretends to be a physician and who dispenses medical advice

quack

(verb) act as a medical quack or a charlatan

quack

(verb) utter quacking noises; “The ducks quacked”

Source: WordNet® 3.1

Etymology 1

Noun

quack (plural quacks)

The sound made by a duck.

Verb

quack (third-person singular simple present quacks, present participle quacking, simple past and past participle quacked)

To make a noise like a duck.

Etymology 2

Noun

quack (plural quacks)

A fraudulent healer or incompetent professional; especially, a doctor of medicine who makes false diagnoses or inappropriate treatment; an impostor who claims to have qualifications to practice medicine. [from c. 1630]

A charlatan.

(slang) A doctor.

Synonyms

• medicaster (dated)

• quacksalver

• See also deceiver

Verb

quack (third-person singular simple present quacks, present participle quacking, simple past and past participle quacked)

To practice or commit quackery (fraudulent medicine).

(obsolete) To make vain and loud pretensions.

Synonym: boast

Adjective

quack (comparative more quack or quacker, superlative most quack or quackest) (quacker and quackest are rare, and probably used humorously)

Falsely presented as having medicinal powers.

Source: Wiktionary

Quack, v. i. [imp. & p. p. Qvacked; p. pr. & vb. n. Quacking.] Etym: [Of imitative origin; cf. D. kwaken, G. quacken, quaken, Icel. kvaka to twitter.]

1. To utter a sound like the cry of a duck.

2. To make vain and loud pretensions; to boast. " To quack of universal cures." Hudibras.

3. To act the part of a quack, or pretender.

Quack, n.

1. The cry of the duck, or a sound in imitation of it; a hoarse, quacking noise. Chaucer.

2. Etym: [Cf. Quacksalver.]

Definition: A boastful pretender to medical skill; an empiric; an ignorant practitioner.

3. Hence, one who boastfully pretends to skill or knowledge of any kind not possessed; a charlatan. Quacks political; quacks scientific, academical. Carlyle.

Quack, a.

Definition: Pertaining to or characterized by, boasting and pretension; used by quacks; pretending to cure diseases; as, a quack medicine; a quack doctor.

Source: Webster’s Unabridged Dictionary 1913 Edition