I. ˈkwak intransitive verb
( -ed/-ing/-s )
Etymology: imitative
1. : to make the characteristic cry of a duck
2. : to make a noise resembling the cry of a duck
II. noun
( -s )
1. : the cry of the duck or a sound in imitation of it
2. : a hoarse quacking noise
the brisk quack of the radio — Sinclair Lewis
III. noun
( -s )
Etymology: short for quacksalver
1. : a pretender to medical skill : medical charlatan : ignorant or dishonest practitioner
one of the most notorious cancer-cure quacks of the day — Journal American Medical Association
2. : one who professes skill or knowledge in any matter of which he knows little or nothing : charlatan
a quack , both as scientist and as historian — G.W.Johnson
to distinguish between the expert and the quack — Walter Moberly
IV. verb
( -ed/-ing/-s )
intransitive verb
1. : to make vain and loud pretensions especially of medical ability : play the quack
2. : to talk pretentiously without sound knowledge of the subject discussed
transitive verb
: to make extravagant claims for as a cure-all : advertise with fraudulent boasts
V. adjective
: relating to or marked by boasting and unfounded pretension : used by quacks : pretending to cure diseases
a quack medicine
a quack doctor
quack claims
quack theology
quack weather prophet