Green’s Dictionary of Slang

1. a rogue or rascal.

1599		Jonson Every Man Out of his Humour II i: These be our nimble spirited catsos, that have their evasions at pleasure.
1606		Wily Beguiled 45: She must recount her many griefes [...] And so cunningly temporize with this cunning Catso.
1611		Davies of Hereford Scourge of Folly 86: To haue a wily ouer-wittie wife, Is (though a Catso) to be made a foole.
1822		R. Nares Gloss. (1888) I 144: catso. A low-lived term of reproach, borrowed from the Italians by ignorant travellers, who probably knew not its real meaning. Used to signify a rogue, cheat, or base fellow.

2. (also cadzo, carts, cartso, cartsue, catzo, cazzo) the penis.

1611		Florio Queen Anna’s New World of Words n.p.: Cazzipotente, mighty in a Cazzo.
1651		A. Weldon Court of King James 99: [He was not only] an excellent Musician [but] had a Catzo of an immense length and bignesse, with this, being his Tabor stick, his palme of his hand his Tabor, and his mouth his Pipe, he would so imitate a Tabor and Pipe, as if it had been so indeed: To this Musicke the ladies would dance ever after Supper; [...] and it was beleeved, that some of them danced after that Pipe without the Tabor.
1653		Urquhart (trans.) Gargantua and Pantagruel (1927) I Bk 1 152: Doth not he die like a good fellow that dies with a stiff catso?
1671		‘Haymarket Hectors’ in Lord Poems on Affairs of State (1963) I 168: Consulting his cazzo, he found it expedient / To engender Don Johns on Nell the comedian.
1680		‘Ballad on Betty Felton’ in Wilson Court Satires of the Restoration (1976) 48: Quickly chastizes all pricks in rebellion, / And is able to break a whole catso battalion.
1686		‘On the Ladies of Honour’ Harleian Mss. 7319.427: Hermaphrodite Frenchvile with Louther her Friend With Cadzo & Dildo full often have Sin’d.
1846		Swell’s Night Guide 107/2: Ace of spades [...] see pego and cartsue.
1890–1904		Farmer & Henley Sl. and Its Analogues.
1896		Farmer Vocabula Amatoria (1966) 57: Catze, m. The penis; ‘the catzo’.
1962		R. Hauser Homosexual Society Appendix 3 167: Cartso, penis.
1972		B. Rodgers Queens’ Vernacular 49: the penis [...] cartso (Brit gay sl, fr It cazzo = penis).
1982		Maledicta VI:1+2 (Summer/Winter) 139: Parlyaree in homosexual use […] gives us [...] cartso = penis, from Italian cazzo.
2001		‘Polari’ on Equity Alliance 🌐 Carts: Cock and Balls.
2019		P. Baker Fabulosa 290/1: cartes, cartzo genitals, especially penis.
2023		R. Milward Man-Eating Typewriter 43: A grandiose multisexual throbbering cartso.

3. in fig. use of sense 2, courage.

1846

Swell’s Night Guide 60: So nanty widding about pluck and cartsue; the biggest dogs dosn’t awlus wag the longest tails, you know.