Green’s Dictionary of Slang

cat n.2

[Ital. cazzo, the penis/abbr. catso n. (2) or the perceived lecherousness of a SE tomcat]

the penis; esp. in phr. a bit for one’s cat.

[UK]Middleton Women Beware Women I ii: Your cats are always safe ith’ chimney-corner, unless they burn their coats.
[UK] ‘Loving Chamber-Maid’ in Euing Broadside Ballads (1971) 179: And if I be clap’d too then what of all that, Some Country Clown will be baiting his Cat.
[UK] ‘Tryal of Skill’ in Pepys Ballads (1987) IV 303: You would have made her your Harlot ... You wanted a Bit for your Cat.
[UK]G. Meriton In Praise of York-shire Ale 53: I blush to tell what follow’d after that, Young Men will have a bit Tibb for their Cat.
[UK]Comforts of Whoreing 28: [Drinking] a Pint of Prickt Claret at some Hedge Tavern ... whilst the Young Spark at home is purchasing a Bit of Tripe to feed his Hungry Cat withal.

In compounds

cat food (n.)

(US black) sexual intercourse.

[US]E. De Roo Big Rumble 58: ‘What should I tell you is that I’m a real cat. But you’d find out soon enough — I’m not.’ ‘But you like cat food, don’t ya?’.
[US]W. Brown Tragic Magic 72: If brothers knew that if they shucked and jived, the sisters wouldn’t get up off any cat food, they would get their shit together in a hurry.

In phrases

skin the cat (v.)

to have sexual intercourse; thus cat-skinning n.

[UK] ‘Slashing Costermonger’ Cuckold’s Nest 11: My vife, she’s such a taste refined, / All hearts she must be vinning, / For ven the turfing trade is bad, / She gets blunt by cat skinning.
[UK]Globe (London) 19 Sept. 4/6: He was ‘undermining her karacter’ by giving out that she’d got three months in quod for ‘cat skinning’.
[US]E. Folb Runnin’ Down Some Lines 151: Terms of intercourse like [...] do the pussy or skin the cat.