Green’s Dictionary of Slang

1. (US) the penis.

1740		‘Roger Pheuquewell’ Description of Merryland (1741) 47: Beware of anchoring in foul Ground; for here is some much gruffer than others, and a great deal so very bad, that it will soon spoil the best of Cables; the sandy or grey Ground are not good to anchor in, the brown is best, in my Opinion.
1997		J. Lansdale Bad Chili 199: They dress a certain way, ’specially if they’re tryin’ to get their cable up a butt.

2. (UK und.) a watch-chain.

1867

Kendal Mercury 9 Mar. 4/2: Had you seen the ticker and the yellow cable hanging down, you’d ha made the grab yourself.

3. (US black) a thick gold chain.

1995

L. Stavsky et al. A2Z.

4. a (long) piece of excrement, usu. in lay a/some cable, to defecate.

1979		Maledicta III:1+2 24: You can go lay a cable, or do number two, / Or sit on the toidy and make a do-do.
1996		(con. 1964-65) B. Thorpe Sex and Thugs and Rock ’n’ Roll 34: A cable worthy of [...] The Guiness Book of Records hit the shitter bowl.
1997–2001		Online Sl. Dict. 🌐 lay cable v 1. to defecate.
2000		N. Griffiths Grits 316: Oo. Big one ther. Birruver ring-stinger, that . . . a red-wine dump, poo, mud-out, crap, shite [...] Layin some transatlantic cable.
2001		G. Coughlan Everyday Eng. and Sl. 🌐 Layin’ a cable (phr) : taking a crap.