Green’s Dictionary of Slang

horse and cart n.

[rhy. sl.]

1. the heart.

[UK]J. Ware Passing Eng. of the Victorian Era. 🌐 Horse and Cart is Cockney slang for Heart.

2. (Aus.) the start.

[Aus]Duke Tritton’s Letter n.p.: I think I had better tell you the Grim and Gory right from the Horse and Cart.
[Aus]Pete’s Aussie Sl. Home Page 🌐 horse and cart: the start.

3. a tart.

[UK]Dodson & Saczek Dict. of Cockney Rhy. Sl.

4. a breaking of wind [= fart n. (1)].

[Aus]Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Horse and cart. Flatulence. Rhyming slang for fart.
[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 90/2: horse and cart n. a fart.
[UK]B. Dark Dirty Cockney Rhy. Sl.