Green’s Dictionary of Slang

a long time; esp. in phr. for yonks.

1968		Daily Mirror (L) 27 Aug. 7/1: I rang singer Julie Driscoll [...] She said: ‘I haven’t heard from you for yonks.’.
1977		‘Jonathan Gash’ Judas Pair in Lovejoy Omnibus (2013) [ebook] Any man that says he can remain celibate for yonks on end is not quite telling the truth .
1983		S. Gee Never in My Lifetime in Best Radio Plays (1984) 74: tessie: Our lot have always been sticks. Granda says it’s the famine. tom: That was yonks ago.
1985		B. Humphries Traveller’s Tool 7: Publishers have been putting the hard word on me for yonks to spill the beans, tell it like it is and tip the bucket.
1998		P. McCabe Breakfast on Pluto 198: My escort work I gave up yonks ago.
2006		D. Mitchell Black Swan Green 15: Your phone was ringing for yonks.
2009		P. Temple Truth 187: Haven’t been here for yonks.
2012		(con. 1980s) I. Welsh Skagboys 82: —We should huv a proper conversation [...] —We did . . . yonks ago.
2014		me-stepmums-too-fuckin-hot-mate at www.fakku.net 🌐 I’ve had...the thought of you in your knickers in me spank bank for yonks.
2021		P. Papathanasiou Stoning 52: ‘It was yonks ago, decades’.
2024		J. Meades Empty Wigs (t/s) 313: This was yonks before musicians and their managers started brown-nosing royalty by funding polo teams.