Cognate with Saterland Frisian kwoakje, kwaakje (âto quackâ), Middle Low German quaken (âto quack, croakâ), German quaken (âto quack, croakâ), Danish kvÃ¦kke (âto croakâ), Swedish kvÃ¤ka (âto croak, quackleâ), Norwegian kvekke (âto croakâ), Icelandic kvaka (âto twitter, chirpâ). The sound made by a duck.