Green’s Dictionary of Slang

1. (orig. US, also yacki, yack-yack, yak-yak) empty, tedious, trivial talk.

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 22: Never mind all that yak-yak. I can’t stay up here all day.
1946		E. Hill ‘Santa Claus of Christmas Creek’ in Rees Aus. Radio Plays 190: A camp of blacks, two or three girls to speak, a little crowd to make ‘yacki’ and sing carols.
1952		B. Appel Plunder (2005) 239: We’re not strangers any more, with all that geisha yack-yack between us.
1954		J.D. MacDonald All These Condemned (2001) 60: Wilma gave me some yak on the phone [...] Something about saving money.
1954		A. Petry Narrows 85: For the love of God, will you guys stop that yak-yak.
1965		W. King ‘The Game’ in King Black Short Story Anthol. (1972) 306: Through the yak-yak, Mac began to tell us the ‘unusual thing’ that he had just recently done.
1967		P. Thomas Down These Mean Streets (1970) 10: The door opened and put an end to the kitchen yak.
1972		Bee (Danville, VA) 27 Sept. 4/1: All of that yak-yak [...] is just a lot more hog-wash and sheep dip.
1973		(con. 1934) E. Williams Emlyn 323: A good yack-yack gets the ball rolling.
1984		‘Derek Raymond’ He Died with His Eyes Open 111: I want to be a temporary member, that’s all, and without a lot of yack.
1998		P. Doyle (con. late 1950s) Amaze Your Friends (2019) 21: We had a yack about the old days.
2009		J. Stahl Pain Killers 353: ‘Try to find anybody else with my talent.’ ‘Yak yak yak’.
2021		J. Ellroy Widespread Panic 134: Connie and her cell siblings suck up Soviet yak-yak and proudly proclaim it as truth.
2023		F. Bill Back to the Dirt 127: ‘Listen to their stuttering yik yak of half-assed mojo’.

2. (US, also yak-yak) a laugh, a joke.

1949		J. Archibald ‘State Penmanship’ Popular Detective Jan. 🌐 If I won’t git nothin’ else, I might git a yak yak out of it.
1952		L. Lariar Day I Died 184: ‘Luke work for Masterson?’ he roared [...] ‘That’s a real bellylaugh, Coyle, a real yak.’.
1957		‘Ed Lacy’ Lead With Your Left (1958) 25: Everybody treats this as a big yak.
1983		R. Price Breaks 227: His yak-a-minute bottom line act vanished.

3. attrib. use of sense 2.

1962

S. Longstreet Flesh Peddlers (1964) 198: Can you see me doing my top yak routines on a boat for deadheads?

4. (US, Western) a fool.

1954

Indep. Record (Helena, MT) 9 Oct. 3/7: Other westerners might be [...] swivel dudes and yacks (i.e. – gaudy fellows and stupid ones).

5. the mouth.

1957

H. Ellison ‘Sob Story’ in Deadly Streets (1983) 148: Why didn’t the damned woman keep her jack-yack shut?

6. (US campus, also yag) 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.
1991		Eble Campus Sl. Fall 6: yak – vomit.

7. (Aus.) with no pejorative implied, a conversation, a talk.

2005

P. Temple Broken Shore (2007) [ebook] ‘Like a good yarn, don’t you? Big talker.’ ‘Love a yack’.