Quack (?), v. i. [imp. & p. p. Qvacked (?); p. pr. & vb. n. Quacking.] [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.
© Webster 1913.
Quack, n.
1.
The cry of the duck, or a sound in imitation of it; a hoarse, quacking noise.
Chaucer.
2. [Cf. Quacksalver.]
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.
© Webster 1913.
Quack, a.
Pertaining to or characterized by, boasting and pretension; used by quacks; pretending to cure diseases; as, a quack medicine; a quack doctor.
© Webster 1913.