Green’s Dictionary of Slang

inconsequential chatter.

1954		B. Appel Sweet Money Girl 95: Yacking! God, what a yacking.
1958		(con. 1950) E. Frankel Band of Brothers 4: You people quit your yackin’.
1959		(con. 1940s) ‘David Forrest’ Last Blue Sea 184: A court-martial can’t kill me. Neither can a lot of yakking about manhood.
1976		P. Theroux Family Arsenal 18: Mr Gawber was glad to [...] hurry away from the yakking that accused him of obscure errors.
1978		R. Caron Go-Boy! 19: Quit the yacking and straighten out that goddam line.
1999		G. Seal Lingo 2: Although mostly taken for granted, the importance of the vernacular in everyday life is apparent from the number of Lingoisms describing or referring to it [...] earbashing; yabber; yacking; verbal diarrhoea.