What does the word quack mean?

Usage examples for quack

  1. The player on the opposite side of the break in the circle proceeds to pass under this arch, the entire circle following, all holding hands and answering Quack! – Games for the Playground, Home, School and Gymnasium by Jessie H. Bancroft
  2. And he seized the black duck by the neck, And slung him all across his back, The black duck cried out " quack, quack, quack," With his legs all dangling down- o! – More English Fairy Tales by Various
  3. You will quickly see that the drift of such publication was only to sell off some Packets of Quack Remedies, and hedge you into his clutches, where 'tis odds but he will pinch, if he does not gripe you to death. – Primitive Psycho-Therapy and Quackery by Robert Means Lawrence