Green’s Dictionary of Slang

not worth a fuck phr.

also not worth a tuppenny frig
[fuck n. (1a)]

absolutely worthless.

[US]V. Spivey ‘Sweet Pease’ 🎵 When I first met you I thought I fell in good luck / Now I know you ain’t worth a — [i.e. fuck] .
[US]D. Jenkins Dead Solid Perfect 142: ‘[Y]ou tell that goddamn, lousy, rotten piece of shit that it never was worth a fuck of anything’.
[US]T. Harrison V [poem] ‘Listen, cunt!’ I said, ‘before you start your jeering / the reason why I want this in a book / ’s to give ungrateful cunts like you a hearing!’ / A book, yer stupid cunt, ’s not worth a fuck!
[Ire](con. 1945) S. McAughtry Touch and Go 150: I’m not worth a tuppenny frig.
[US]C. Carr Our Town 283: ‘The judicial system ain’t worth a fuck,’ she concluded.