quack

From Middle English *quacken, queken (“to croak like a frog; make a noise like a duck, goose, or quail”), from quack, qwacke, quek, queke (“quack”, interjection and noun), also kek, keke, whec-, partly of imitative origin and partly from Middle Dutch quacken (“to croak, quack”), from Old Dutch *kwaken (“to croak, quack”), from Proto-West Germanic *kwakōn, from Proto-Germanic *kwakaną, *kwakōną (“to croak”), of imitative origin. Cognate with Saterland Frisian kwoakje, kwaakje (“to quack”), Middle Low German quaken (“to quack, croak”), German quaken (“to quack, croak”), Danish kvække (“to croak”), Swedish kväka (“to croak, quackle”), Norwegian kvekke (“to croak”), Icelandic kvaka (“to twitter, chirp, quack”).