Green’s Dictionary of Slang

1. an act of defecation; a piece of excrement.

1931		E. Blair letter 4 Sept. in Complete Works X (1998) 228: As to new words, here are some [...] Pony = a shit.
1958		(con. 1940s) B. Behan Borstal Boy 245: Why doesn’t he have his pony and trap in their time?
1969		S.T. Kendall Up the Frog.
1977		G.F. Newman A Prisoner’s Tale 34: There was no way the screws were going to let him out for a pony.
1981		P. Wright Cockney Dialect and Sl. 107: Another is pony for pony and trap.
1996		P. Howard The Joy (2015) [ebook] I can feel an auld pony and trap coming on. So I just sit on me piss-pot in the corner and let nature take its course.
1999		J. Cameron Brown Bread in Wengen [ebook] [T]he gents’ toilet by the bus station. Quiet and slippery, no one ever went in there for a pony.
2004		N. ‘Razor’ Smith A Few Kind Words and a Loaded Gun 109: Both me and Jel had a pony in a paper bag [...] We waited until he was under our cell, then launched the shit-parcel down on top of him.

2. in fig. use, nonsense, rubbish; also attrib.

1956		‘Charles Raven’ Und. Nights 24: We know that’s a lot of pony-and-trap. [Ibid.] 165: I mean all. All the good stuff as well as all the pony.
1982		J. Sullivan ‘Ashes to Ashes’ Only Fools and Horses [TV script] Oh come on, you don’t believe all that pony, do yer?
1996		K. Lette Mad Cows 19: How do we know that’s not a load of old pony?
2012		(con. 1980s) I. Welsh Skagboys 453: We presented him with this pony letter in whichn we told him why we’d miss him.

3. difficulties, problems.

2002

D. Shaw ‘Dead Beard’ at www.asstr.org 🌐 I’ve certainly got her attention because she doesn’t remember me at all and being recognized anywhere could land her right in the pony and trap.

4. silver items [the inference is the relative worthlessness of such items as compared with gold].

1941

V. Davis Phenomena in Crime 253: Pony and trap. Silver articles.

5. imitation jewels.

1956

‘Charles Raven’ Und. Nights 88: The rest is all pony-and-trap, jargoon, in other words im-i-tashun.

6. loaded dice.

1989

(con. 1920s) Courtwright & Des Jarlais Addicts Who Survived 294: He was asked how he accounted for his ill-luck, and he laughingly replied, ‘I guess the blokeys use ponies (loaded dice) on me’.