An Etymological Dictionary of the German Language/Annotated/gackern

by Friedrich Kluge

gackern, gacksen, verb, ‘to cackle, chatter,’ simply Modern High German; imitative forms like Middle High German gâgen, ‘to cackle like a goose.’ akin to Dutch gagelen, ‘to gabble,’ and even in Old High German gackizôn, ‘to mutter,’ gagizôn, gackazzen, ‘to bawl,’ Middle High German gagzen, ‘to cluck like a hen laying.’ Compare Scandinavian gagga, ‘to howl like a fox,’ gagl, ‘wild goose,’ English to gaggle.