Gabban

According to the Old English Dictionary:

gabban

p. ede; pp. ed To scoff, mock, delude, jest; hence, perhaps, GABBLE, GIBBERISH; derīdĕre, lūdĕre, illūdĕre, Som. Ben. Lye. [Prompt. gabbin mentiri : Piers P. gabbe to lie : Chauc. to chatter, lie : Scot. gab to mock, prate : Icel. gabba to mock.] gabbung,gabban,gabere