quack 1
/kwak/ , n.
1. the harsh, throaty cry of a duck or any similar sound.
v.i.
2. to utter the cry of a duck or a sound resembling it.
[ 1610-20; imit.; cf. D kwakken, G quacken ]
quack 2
— quackish , adj. — quackishly , adv. — quackishness , n.
/kwak/ , n.
1. a fraudulent or ignorant pretender to medical skill.
2. a person who pretends, professionally or publicly, to skill, knowledge, or qualifications he or she does not possess; a charlatan.
adj.
3. being a quack: a quack psychologist who complicates everyone's problems.
4. presented falsely as having curative powers: quack medicine.
5. of, pertaining to, or befitting a quack or quackery: quack methods.
v.t.
6. to treat in the manner of a quack.
7. to advertise or sell with fraudulent claims.
[ 1620-30; short for QUACKSALVER ]
Syn. 2. mountebank, phony.