Green’s Dictionary of Slang

screwball n.

[screwy adj. (4a) + -ball sfx; note baseball use screwball, a ball pitched with reverse spin against the natural curve]

1. (orig. US, also screwbox) an eccentric, an out-of-the-ordinary person.

[US]P. Di Donato Christ in Concrete 235: Goddamn-damn sonofabastarddd I said brick on the hoist – not tile! Brick you dago screwball!
[UK]Wodehouse Uncle Fred in the Springtime 115: ‘You are going to Blandings Castle now, no doubt, to inspect some well-connected screwball?’.
[US]N. Davis ‘Don’t Give Your Right Name’ in Goulart (1967) 10: Screwball is having one of his fits again.
[US]R.O. Boyer Dark Ship 153: Eccentrics are usually called ‘screwboxes’.
[US]‘Hal Ellson’ Tomboy (1952) 133: Roller skates. Do you think we came for that, screwball?
[UK]Wodehouse Jeeves in the Offing 36: Your aunt thinks he’s a screwball.
[US]L. Rosten Dear ‘Herm’ 4: I am getting sick-and-tired of being woke up at 11 P.M.! [...] by screw-balls demanding to know if I am Leo Rosten.
[UK]P. Theroux Picture Palace 66: I had never been so close to such loud strangers – screwballs, swill-pails, fancy signs.
[UK]J. Bradner Danny Boy 75: Oscar didn’t want Danny to end up a ‘screw-ball’.
[US]R. Campbell Sweet La-La Land (1999) 181: Witchcraft ain’t illegal. Just a lot of screwballs jumping bare-assed over swords and fire, kissing the master’s bunghole.
[UK]Guardian 14 Jan. 8: The series portrays Hadfield as if it were populated by every screwball under the sun.
[UK]Guardian 21 Jan. 🌐 Some screwball no-mark in some pointless department.
[US](con. 1991-94) W. Boyle City of Margins 46: ‘You’re such a screwball’.

2. nonsense.

[US]E. Pound (trans.) Sophocles’ Women of Trachis 20: Just talk, a mere rumour [...] No use bothering with this screw-ball.