Green’s Dictionary of Slang

1. often in pl., the human brain, the mind.

[1858		A. Mayhew Paved with Gold 345: This is a strange kind of gent [...] to dine with his valets. There’s something very deranged in these clock-works].
1943		R.L. Bellem ‘Heads You lose’ in Dan Turner Hollywood Detective Feb. 🌐 Butterflies were fluttering in my clockworks as I lurched to my cellarette for a fresh fifth of Vat 69.
1947		M.H. Boulware Jive and Sl. n.p.: Clockworks ... Brains.

2. the female buttocks.

2000

Ebonics Primer at www.dolemite.com 🌐 clock-work Definition: a woman’s butt. Example: Damn, that’s a fine ass piece of clock-work.