Definition of quack quack in English:

quack quack

Pronunciation /ˌkwak ˈkwak/ /ˈkwak ˌkwak/

exclamation

  • Representing the harsh sound characteristically made by a duck, or a noise resembling this.

noun

humorous, informal
  • A duck.

Origin

Late 17th century; earliest use found in Edward Ravenscroft (fl. 1659–1697), playwright. Reduplication of quack.