Green’s Dictionary of Slang

to make a mess of, to ruin, to blunder, to make a mistake.

1894		Freeland Tribune (PA) 2 Aug. 2/2: If a person feels a little peckish [...] he forthwith chucks into his interior a gob of the indigestible stuff [...] to appease for the moment the yearn for something to eat, but at the same time balls up his internal mechanism.
1903		Washington Times (DC) 28 July 6/1: His aggressive campaign [...] ‘mars the symettery and balls up the efficiency’ of the Postoffice Department.
1935		(con. 1920s) J.T. Farrell Judgement Day in Studs Lonigan (1936) 650: I’ve been balling myself all up with my system of handicapping.
1947		D. Davin For the Rest of Our Lives 112: If only they haven’t ballsed up the bomb-line we gave them.
1967		N. Dunn Poor Cow 129: I’d fuck meself up talking, I always get ballsed up talking to the upper classes.
1976		C. Dexter Last Seen Wearing in Second Inspector Morse Omnibus (1994) 515: It’s some clown of a sergeant who’s ballsed the whole thing up.
1981		A. Weller Day of the Dog 161: He ballsed it up.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 201: Colette really...ballsed things up in her own funny sort of way.
1989		H. Rawson Dict. of Invective (1991) 31: To bollix up, which is the same as the newer ball up (foul up, or balls-up in British English).
1998		Guardian Sport 18 Sept. 16: To make sure that Man. U. qualify for the knockout even if they balls up the group stage.
1999		Guardian G2 19 Aug. 9: The first time I knew you, I really ballsed it up, didn’t I?
2001		A. Sillitoe Birthday 97: The traffic was flowing like water, not a hitch anywhere, so what about another one-way system, to balls it all up?
2009		T. Black Gutted 235: Gus, we have a chance here [...] Let’s not balls it up.
2015		N. Cummins Tales of the Honey Badger [ebook] I was so focused on not ballsing things up.
2021		L. McInerney Rules of Revelation 308: She’d ballsed it up. Tried tough love, wanted him to confront the big bad memory. I prescribed whiskey.