Green’s Dictionary of Slang

1. (also yak it up, yak-yak) to chatter tediously.

[1934		Northern Standard (Darwin) 24 Apr. 3/2: Dead Dolly been yacki, ‘Leave me alone, boss, please’ ].
1949		Kerouac letter 10 June in Charters I (1995) 195: I heard a night-bird warbling in a living tree; / and a queer house there was that yakked at me.
c.1951		N. Algren ‘Watch Out for Daddy’ in Entrapment (2009) 148: I just feel like yakking [...] for a while.
1952		W.R. Burnett Little Men, Big World 114: I’ll take Lola along. She’s always yacking she never gets out of the district.
1957		R. Prather Always Leave ’Em Dying 113: Primarily it was just an interesting story, something novel to yak about.
1959		W. Brown Teen-Age Mafia 5: Whiter Carew was doing the talking. Yakking it up big.
1961		Mad mag. July 28: They found out there wasn’t a single dirty word in it for members to yak and shriek at.
1965		F.J. Hardy Yarns of Billy Borker 56: ‘Listen Sheckles,’ he says, ‘you are always yak-yaking about how much money you’re making.’.
1968		D. O’Grady A Bottle of Sandwiches 130: I spent the time yacking to all and sundry.
1971		N. Smith Gumshoe (1998) 21: I could tell she was Welsh because she was yacking into the ’phone in that language.
1974		(con. 1960s) R. Price Wanderers 211: Handsome men and beautiful women stood around his bed with drinks in their hands, yakking away.
1977		(con. 1949) J.G. Dunne True Confessions (1979) 156: She and Mary Margaret would have gotten along good, yakking it up with all the saints there.
1984		(con. WW2) T. Jones Heart of Oak [ebook] Yak this, yak that, the pusser-faced bastard never stops yakking.
1987		T. Wolfe Bonfire of the Vanities 47: A balding young white man [...] just standing there talking, smiling, yakking.
1989		M. Amis London Fields 173: She doesn’t just plonk herself on a chair, like some. Yack yack yack.
1993		Tarantino & Avery Pulp Fiction [film script] 45: Why do we feel it’s necessary to yak about bullshit.
1999		Observer Rev. 28 Nov. 5: A Serb reporter started yacking on about Northern Ireland.
2004		C. Hiaasen Skinny Dip 154: Damn if Oprah wasn’t yakking with three movie actresses.
2008		R. Price Lush Life 24: Little Dap Williams yakking away .
2012		Guardian 7 Mar. 🌐 We do not like to yak about ourselves.
2013		T. Robinson Hard Bounce [ebook] ‘Fast friends, They were yakking it up’.
2018		G. Disher Kill Shot [ebook] Muecke thought they were going to [...] stand around yacking.
2023		Rayman & Blau Riker’s 348: So at one point the mayor is yakking to someone from the community.

2. to render humorous.

1954

Mad mag. June 17: So in order to make people laugh [...] we have yakked up the ending of this story.

3. (US campus, also yag) to vomit.

1989		M. Belmonte Compter Science and Why (1993) 🌐 I was struck with [...] the plethora of words and phrases meaning ‘vomit’ and/or ‘to vomit’ [...] At most American colleges and universities, a weekend cannot pass without seeing multitudes [...] yag, yak.
1989		P. Munro Sl. U. 209: yak to vomit.
1993		M. Myers et al. Wayne’s World II [film script] If I yack, chances are someone else will chunder.
1996		Eble Sl. and Sociability 42: The slightly different ook, yuke, yuck, and yak all mean ‘vomit.’.
2002		O’Byrne Files: Dublin Sl. Dict. 🌐 Ger scoffed that Abrekebabra chip butty, after ten pints, and yacked all over the bog!
2003		Eble Campus Sl. Nov. 8: yak – vomit.
2016		C. Eble (ed.) UNC-CH Campus Sl. Spring 2016.

4. (UK black/gang, also yak) to assault and rob.

2018		Unknown T ‘Mad about Bars’ 🎵 Your boy got yakked then bounced, twice.
2018		Unknown T ‘Mad about Bars’ 🎵 He got splashed, but your team don't back / He got yacked, and he got wrapped.
2020		G. Krauze What They Was 39: [O]ne by one he’d yack every single cat, bareface.