[Imitative: cf. Du. kwak, G. quack, Sw. qvack (of ducks or frogs), Icel. kvak twittering of birds. See also QUAKE int.] The harsh cry characteristic of a duck; a sound resembling, or imitating this. b. humorously. A duck.
1839. Lett. fr. Madras (1843), 290. Showing his teeth, and uttering a loud quack!
1869. Blackmore, Lorna D., x. He gave me a look from his one little eye … and then a loud quack to second it.
a. 1897. Bird o’ Freedom (Barrère & Leland). I send her herewith a couple of quacks.
1901. A. R. Conder, Seal Silence, 206. The voice of the footman rose high above the general quack of conversation.
