Noun
- a sound made by a duck.
- Did you hear that duck make a quack?
- a fraudulent doctor of medicine, an impostor who claims to have qualifications to practice medicine.
- That doctor is nothing but a lousy quack!
- a charlatan.
- What a quack he is saying that's an organic Viagra ™!
- (slang) a doctor.
Translations
- Dutch: kwak (1), kwakzalver (2, 3)
- French: coin-coin (1) m; charlatan m (2, 3); toubib m (4)
- Indonesian: kwek-kwek (1), gadungan (2, 3)
- Interlingua: quac (1)
- Italian: qua qua (1) m; ciarlatano (2, 3); dottore (4)
- Spanish: cuac (1); curandero m (2)
Adjective
- falsely presented as having medicinal powers.
- Don't get your hopes up; that's quack medicine!
Verb
- to make a noise like a duck.
- The more breadcrumbs I threw on the ground, the more they quacked.
- Do you hear the ducks quack?
Translations
- Dutch: kwaken
- French: faire coin-coin
- Interlingua: quaccar
- Italian: fare qua qua
- Spanish: decir cuac
