Quack
Quack , intransitive verb
[Of imitative origin; compare Dutch kwaken, German quacken, quaken, Icelandic 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.
3.
To act the part of a quack, or pretender.
Quack , noun
1.
The cry of the duck, or a sound in imitation of it; a hoarse, quacking noise. — Chaucer
2.
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.
Quack , adjective
Pertaining to or characterized by, boasting and pretension; used by quacks; pretending to cure diseases; as, a quack medicine; a quack doctor.